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Mechanism of cross-level settlements and void accumulation of wide and conventional sleepers in railway ballast

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Railway Engineering science 2024年第3期32卷 361-383页

作者： Olga Nabochenko Mykola sysyn norman Krumnow szabolcs Fischer Institute of Railway systems and Public Transport Technical University of DresdenDresdenGermany Rhomberg sersa Deutschland GmbH BerlinGermany Central Campus Győr Széchenyi István UniversityGyorHungary

The cross-level and twist irregularities are the most dangerous irregularity types that could cause wheel unloading with the risk of derailments and additional maintenance ***,the mechanism of the irregularities initiation and development is *** motivation of the present study was the previous experimental studies on the application of wide sleepers in the ballasted *** long-term track geometry measurements with wide sleepers show an enormous reduction of the vertical longitudinal irregularities compared to the conventional ***,wide sleepers had higher twist and cross-section level *** present paper aims to explain the phenomenon by discrete element method(DEM)modeling the development process of sleeper inhomogeneous support at cross-level depending on the sleeper *** DEM simulations show that the maximal settlement intensity is up to 3.5 times lower for a wide sleeper in comparison with the conventional ***,the cross-level differential settlements are almost the same for both *** particle loading distribution after all loading cycles is concentrated on the smaller area,up to the half sleeper length,with fully unloaded zones under sleeper *** flow limitation under the central part of the sleeper could improve the resilience of wide sleepers to the development of cross-level *** mechanism of initiation of the cross-level irregularity is proposed,which assumes the loss of sleeper support under sleeper *** further growth of inhomogeneous settlements along the sleeper is assumed as a result of the interaction of two processes:ballast flow due to dynamic impact during void closing and on the other side high pressure due to the concentration of the pressure under the middle part of the *** DEM simulation results support the assumption of the mechanism and agree with the experimental studies.

关键词： Wide sleeper Ballasted track sleeper support inhomogeneity sleeper foot form Discrete element modeling Void accumulation

Diet variability of snappers(Teleostei:Lutjanidae)in a bay-to-reef ecosystem of the Mexican Caribbean

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Water Biology and security 2024年第1期3卷 53-59页

作者： Leon Felipe Martínez-Juarez Juan J.schmitter-soto Nancy Cabanillas-Teran norman Mercado-silva El Colegio de la Frontera sur 77014ChetumalQuintana RooMexico Centro de Investigacion en Biodiversidad y Conservacion Universidad Autonoma del Estado de Morelos62209CuernavacaMorelosMexico

Fishes use environmental resources *** ontogenic movements among coastal habitats lead to diverse *** investigated the diets of seven snapper species(Lutjanus apodus,***,***,***,***,***,and Ocyurus chrysurus)in three interconnected coastal environments in the western Caribbean:Río Huach channel,Chetumal/Corozal bay,and the adjacent Xcalak reef *** three encompass all habitats used by the seven species in the study *** diets were mostly composed of fish and crustaceans,but dominance of either group varied among the studied habitats;for example,fish were the main prey for *** from the reef lagoon zone,but second in the *** are piscivorous-invertivorous mesopredators;the species that relied the most on fishes were *** and ***,whereas *** preferred *** content results revealed a high degree of dietary overlap among *** findings suggested a tradeoff in relative weight between fish and crustaceans as the main food source of snappers at these connected areas,supporting the hypothesis of niche *** results can be used as a baseline to further our understanding of the ecology and differences in resource use by snapper species in an area undergoing important anthropogenic changes.

关键词： Resource partitioning Chetumal/Corozal bay Quintana Roo Trophic ecology

Genetic and Agronomic Parameter Estimates of Growth, Yield and Related Traits of Maize (Zea mays L.) under Different Rates of Nitrogen Fertilization

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American Journal of Plant sciences 2024年第4期15卷 274-291页

作者： Prince Emmanuel norman Lansana Kamara Aloysius Beah Kelvin sahr Gborie Francess sia saquee sheku Alfred Kanu Fayia Augustine Kassoh Yvonne sylvia Gloria Ethel norman Abdul salaam Kargbo sierra Leone Agricultural Research Institute (sLARI) Freetown Sierra Leone school of Agriculture Njala University Njala Campus Njala Sierra Leone school of Natural Resources Management Njala University Njala Campus Njala Sierra Leone Department of Agro Biotechnology Institute of Agriculture RUDN University Moscow Russia Faculty of Development Agriculture & Natural Resources Management Eastern Technical University of Sierra Leone Kenema Sierra Leone

This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-EsR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙hasup>−sup>sup>1sup>) rates. Findings showed that cob diameter and anthesis silking time (AsI) had intermediate heritability, AsI had high genetic advance, AsI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, AsI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p s and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙hasup>−sup>sup>1sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙hasup>−sup>sup>1sup> and 2098 kg∙hasup>−sup>sup>1sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFPsub>Nsub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p se factors. The highest PFPsub>Nsub> (41.3 kg grain kgsup>−sup>sup>1sup>∙N) and AEN (29.4 kg grain kgsup>−sup>sup>1sup>∙N) were obtained in the 30 kg∙N∙hasup>−sup>sup>1sup> plots, while the highest VCR (2.8) and MR (sLL 1.8 sLLsup>−sup>sup>1sup> spent on N) were obtained in the 180 kg∙N∙hasup>−sup>sup>1sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fe

关键词： Nitrogen Rates Genetic and Agronomic Estimates Introduced Genotypes Grain Yield Zea mays

Variation in Yellow Root Cassava (Manihot esculentus Crantz) Genotypes and Phenotypic Relationship for selected Postharvest and Morphological Traits

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Agricultural sciences 2024年第9期15卷 993-1008页

作者： suffian Mansaray Prince Emmanuel norman Joseph sherman-Kamara Isata Kamanda Kadiatu Nannah serry Post-Harvest and Nutrition Sierra Leone Agricultural Research Institute (SLARI) Tower Hill Freetown Sierra Leone Department of Agriculture Engineering School of Technology Njala University Njala Campus Bo Sierra Leone Germplasm Enhancement and seeds system Sierra Leone Agricultural Research Institute (SLARI) Tower Hill Freetown Sierra Leone

This study evaluated the variation in yellow root cassava (Manihot esculentus Crantz) genotypes and phenotypic relationship for selected postharvest and morphological traits. The trial was established at the Njala Agricultural Research Centre experimental site, Njala, during 2017/2018 cropping season in a randomized complete block design with three replications. Findings showed that the higher the total carotene content (TCC) in yellow flesh cassava genotypes, the longer the rate of postharvest physiological deterioration (PPD). Genotypes TR-0051-TCC/17 and TR-0012-TCC/17 recorded higher TCC (18.9 µg/g and 13.6 µg/g) and longer rate of PPD (4.29 and 3.14), respectively. Genotypes TR-0051-TCC/17, TR-0016-TCC/17, TR-0028-TCC/17, TR-0012-TCC/17 and TR-0020-TCC/17 had the highest TCC values of 18.9 µg/g, 16.09 µg/g, 14.72 µg/g, 13.6 µg/g and 11.23 µg/g with corresponding higher color chart values of 6, 6, 6, 5, and 6, respectively. This suggests the direct dependence of TCC on the root parenchyma color intensity in yellow flesh cassava genotypes. Findings also show a direct relationship between morphological and postharvest traits in yellow flesh cassava genotypes that could be exploited for the genetic improvement of cassava for increased shelf life, nutrition and related quality traits, as well as conservation and utilization of the crop.

关键词： Cassava Variability Regression Correlation Postharvest and Morphological Traits

Projected Changes in Extreme Event Indices for Alaska

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Atmospheric and Climate sciences 2024年第2期14卷 191-209页

作者： John E. Walsh Kyle Redilla norman s.ippe. Lukas Cheung David Bigelow Ronni Wilcock International Arctic Research Center University of Alaska Fairbanks Fairbanks USA stantec Ottawa Canada stantec Montreal Canada stantec Calgary Canada Two Bears Environmental Consulting Anchorage USA

As climate has warmed in recent decades, Alaska has experienced a variety of high-impact extreme events that include heat waves, wildfires, coastal storms and freezing rain. Because the warming is projected to continue, it is essential to consider future changes when planning adaptation actions and building resilience. In this study, we synthesize information on future changes in extreme events in Alaska from an ensemble of regional climate model simulations performed as part of Arctic-CORDEX (Coordinated Regional Climate Downscaling Experiment). A set of 13 extreme event indices, based on those developed by the World Climate Research Programme’s Expert Team on Climate Change Detection and Indices (ETCCDI), are evaluated from the Arctic-CORDEX output for Alaska. Of the 13 indices, six pertain to temperature, five to total precipitation, one to wind and one to snow. The results for locations in seven different climate zones of Alaska include large increases (5˚C - 10˚C) in the temperature thresholds for the five hottest and coldest days of the year, and large increases in warm spell duration and decreases in cold spell duration. Changes in the cold day temperature threshold are generally larger than the changes in the hot day temperature threshold, consistent with the projections of a stronger warming in winter than in summer in Alaska yearly maximum 1-day and 5-day precipitation amounts as well as the yearly number of consecutive wet days are projected to increase at all locations. The indices for heavy snow days and high-wind days show mixed changes, although the results indicate increases in heavy snow days at the more northern locations and increases in windy days at coastal locations. The changes in the extreme event indices continue through 2100 under the higher-emission (RCP 8.5) emission scenario, while the changes generally stabilize under the lower-emission (RCP 4.5) scenario. .

关键词： Extreme Events Temperature Precipitation Alaska Climate

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真菌和花卉保护并赞颂大自然

空中英语教室（高级版．彭蒙惠英语） 2024年第8期 20-22,43-45页

作者： Mary Ann Thomas norman Winter 不详

每个人都可以是博物学家查尔斯·毕尔是那种会把蛇放进口袋里的孩子。郊区可能会很无聊。草坪和道路无法为好奇的男孩提供多样的生物。不过,不久之前退休的宾夕法尼亚州西部自然资源保护协会保护科学资深主任毕尔却找到了在野外消磨时... 详细信息

每个人都可以是博物学家查尔斯·毕尔是那种会把蛇放进口袋里的孩子。郊区可能会很无聊。草坪和道路无法为好奇的男孩提供多样的生物。不过,不久之前退休的宾夕法尼亚州西部自然资源保护协会保护科学资深主任毕尔却找到了在野外消磨时间的方式。

关键词：自然资源保护宾夕法尼亚州博物学家大自然

Oviposition site Preference and Its Effects on subsequent Development of Variegated Grasshopper (Zonocerus variegatus L.) under Laboratory Conditions

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Advances in Entomology 2024年第3期12卷 143-154页

作者： saffea Joseph Torto Abu James sundufu Alusaine Edward samura sahr Ngoba Fomba Dennis Peter Musa skeku Alfred Kanu Prince Emmanuel norman Department of Crop Protection School of Agriculture and Food Sciences Njala Sierra Leone Department of Horticulture School of Natural Resources Management Njala University Njala Sierra Leone Department of Crop science School of Agriculture and Food Sciences Njala University Njala Sierra Leone Germplasm Enhancement and seeds systems Sierra Leone Agricultural Research Institute Freetown Sierra Leone

Female grasshoppers can affect the fitness of their offspring through their selection of oviposition site. Knowledge of soil type on oviposition, and its effects on subsequent development can provide guidelines for habitat manipulations that reduce the harmful effects of these pests on farmers fields. The influence of soil types on the oviposition site preference of variegated grasshopper (Zonocerus variegatus L.) reared some cassava (Manihot esculenta Crantz) varieties, was investigated in a cage trial carried out at the Bio factory laboratory, school of Agriculture and Food sciences, Njala University, sierra Leone during 2022/2023. The treatments comprised three soil types (sandy, Loamy and Clay), each with three replications laid out in a randomized complete block design (RCBD) in wooden cages. Data were collected on the following development parameters including, Net reproductive growth ratio (R0), Generation time (Tc), Intrinsic rate of increase (rm), Finite rate of increase (), Doubling time (Dt), and overall survivorship. Findings revealed that, Z. variegatus L. preferred sandy soil in which, on average, most eggs were deposited (338, 6.62 4.40), followed by loamy soil, 286 (5.53 3.96), and then, clayey soil, 200 (3.91 3.85);though, the differences were not significant. This study established that Z. variegatus deposited more eggs in sandy soil > loamy soil > clayey soil, respectively;and subsequent survivorship of the immature unto mature adult insect, revealed a similar order. This indicates that the sandy soil is the most preferred substrate for oviposition and subsequent development into adult insects.

关键词： Development Oviposition Oviposition site Preference soil Types Variegated Grasshopper

Pre-operative visceral adipose tissue radiodensity is a potentially novel prognostic biomarker for early endoscopic post-operative recurrence in Crohn’s disease

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World Journal of Gastrointestinal surgery 2024年第3期16卷 740-750页

作者： Phillip Gu shishir Dube norman Gellada so Yung Choi susan Win Yoo Jin Lee shaohong Yang Talin Haritunians Gil Y Melmed Eric A Vasiliauskas Niru Bonthala Gaurav syal Andres J Yarur David Ziring shervin Rabizadeh Phillip Fleshner Cindy Kallman suzanne Devkota stephan R Targan Dalin Li Dermot PB McGovern Department of Medicine Cedars-Sinai Medical CenterLos AngelesCA 90048United States Department of Imaging Cedars-Sinai Medical CenterLos AngelesCA 90048United States Department of Biostatistics shared Resource Cedars-Sinai Medical CenterLos AngelesCA 90048United States Department of Internal Medicine Keimyung University School of MedicineDaegu 42601South Korea Department of Medicine University of California at Los AngelesLos AngelesCA 90095United States Department of Medicine University of California at San DiegoSan DiegoCA 92093United States Department of Pediatrics Cedars-Sinai Medical CenterLos AngelesCA 90048United States Department of surgery Cedars-Sinai Medical CenterLos AngelesCA 90048United States

BACKGROUND Evidence suggests inflammatory mesenteric fat is involved in post-operative recurrence(POR)of Crohn’s disease(CD).However,its prognostic value is INTRODUCTION Crohn’s disease(CD)is a debilitating chronic immune-mediated inflammatory disease(IMID)of the gastrointestinal tract that is increasing in incidence and prevalence globally[1].CD patients often undergo surgery for disease-related complic-ations and/or medically refractory ***,surgery is not curative,and many patients develop post-operative recurrence(POR)of CD with a significant proportion eventually requiring additional *** advances in early detection and therapeutics,the contemporary 10-year risk of surgery has improved from 50%to 26%,but the risk of recurrent surgery has remained unchanged at 30%,suggesting a need to improve post-operative management strategies[2].Presently,there are two accepted strategies to mitigate POR,but each have potential ***,patients start early post-operative pharmacologic prophylaxis within 4-6 wk after *** strategy can potentially overtreat a subset of patient who may not develop long-term disease recurrence off ***,these patients are at risk of medication-related adverse events and the direct and indirect costs associated with therapy with little or no benefit[3].The second strategy is performing early colonoscopy within 6-12 months after surgery and escalating therapy based on FOOTNOTEs Author contributions:Gu P is the guarantor of the article and was involved in concept and design,data collection,statistical analysis,drafting of manuscript,and final approval of manuscript;Dube s and Choi sY were involved in statistical analysis,drafting of the manuscript,and final approval of manuscript;Gellada N,Win s,Lee YJ and Yang s were involved in the data collection,drafting of the manuscript,and final approval of manuscript;Haritunians T and Li D were involved in data analysis and interpretation,drafting

关键词： Crohn’s disease surgery Visceral adipose tissue Mesenteric adipose tissue Creeping fat Computed tomography

A note on a boundary condition for spouted beds

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Particuology 2010年第6期8卷 536-538页

作者： norman Epstein Department of Chemical&Biological Engineering The University of British Columbia2216 Main MallVancouverB.C.Canada V6T 1Z3

The boundary condition, zero solids pressure at the top of a particle bed of maximum spoutable height, Hm, is shown to eliminate any resort to empiricism in the derivation of the fluid velocity in the annulus of a spouted bed for which both viscous and inertial effects are taken into account. The same boundary condition fails when applied to a spouted bed for which the bed height H 〈 Hm, especially when H 〈 0.8Hm.

关键词： spouted beds Annulus flow Boundary condition Particle-fluid hydrodynamics