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Articles 40411 - 40440 of 302422

Full-Text Articles in Physical Sciences and Mathematics

Duration Of Regrowth Of Ryegrass (Lolium Perenne) Swards: Effects On Rumen Fermentation Of Lactating Dairy Cows, P. Chilibroste, S. Tamminga, H. Boer Nov 2021

Duration Of Regrowth Of Ryegrass (Lolium Perenne) Swards: Effects On Rumen Fermentation Of Lactating Dairy Cows, P. Chilibroste, S. Tamminga, H. Boer

IGC Proceedings (1993-2023)

The relative importance of duration of sward regrowth and rumen fill and fermentation on the control of grazing time and intake rate during the first grazing session of the day were studied. Four lactating dairy cows were allowed to graze ryegrass (Lolium perenne) swards, with five different regrowth periods after mowing (6, 9, 16, 22 and 30 d). The cows were allowed to graze until they stopped voluntarily. Samples of rumen liquid were taken at approximately 0, 30, 60, 120 and 240 min after the grazing session was finished. Concentration of volatile fatty acids (VFA) followed a significant …

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Effective Growing Degree Days As A Critical Factor For Yield And Qualitative Values Of Timothy In Subarctic Growing Conditions, Oiva Nissinen Nov 2021

Effective Growing Degree Days As A Critical Factor For Yield And Qualitative Values Of Timothy In Subarctic Growing Conditions, Oiva Nissinen

IGC Proceedings (1993-2023)

The yield and forage quality of timothy (Phleum pratense L.) leys at different stages of development were studied in 1991-1999 at the Lapland Research Station of the Agricultural Research Centre of Finland in Rovaniemi (66o35´N). The aim of the study was to determine the optimal time for the first cut with respect to yield and qualitative values. In timothy the first heads were visible on 25 June on average and full heading was seen on 5 July, i.e. some ten days later. During this period the dry matter yield increased from 2769 to 4945 kg/ha, crude protein …

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Establishment Of Tanzania Grass Pasture Using Millet As A Companion Crop, José C. Pinto, M. C. Maia, I. F. De Andrade, I. P. A. Dos Santos, E. R. P. Bomfim, K. R. Soares Nov 2021

Establishment Of Tanzania Grass Pasture Using Millet As A Companion Crop, José C. Pinto, M. C. Maia, I. F. De Andrade, I. P. A. Dos Santos, E. R. P. Bomfim, K. R. Soares

IGC Proceedings (1993-2023)

Forage yield and quality of millet [Pennisetum glaucum (L.) R. Br.] and tanzania grass (Panicum maximum Jacq. cv. Tanzania I) were evaluated when grown in mixture. The treatments evaluated were four seed mixture combinations, based on a standard sowing density of 8 kg.ha-1, of tanzania grass/millet (08/00; 05/03; 04/04 and 03/05 kg.ha-1) and three cutting frequencies (1 cutting – 100th day after sowing; 2 cuttings – 50th and 100th days after sowing and 3 cuttings – 40th, 70th and 100th days after sowing), in a randomized complete block design, with four replications, in a …

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Mgrre_Pureoilscouttickets_White River Land Co Tract_1_21127059350000, Mgrre Nov 2021

Mgrre_Pureoilscouttickets_White River Land Co Tract_1_21127059350000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

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Multi-Task Learning Of Order-Consistent Causal Graphs, Xinshi Chen, Haoran Sun, Caleb Ellington, Eric Xing, Le Song Nov 2021

Multi-Task Learning Of Order-Consistent Causal Graphs, Xinshi Chen, Haoran Sun, Caleb Ellington, Eric Xing, Le Song

Machine Learning Faculty Publications

We consider the problem of discovering K related Gaussian directed acyclic graphs (DAGs), where the involved graph structures share a consistent causal order and sparse unions of supports. Under the multi-task learning setting, we propose a l1/l2regularized maximum likelihood estimator (MLE) for learning K linear structural equation models. We theoretically show that the joint estimator, by leveraging data across related tasks, can achieve a better sample complexity for recovering the causal order (or topological order) than separate estimations. Moreover, the joint estimator is able to recover non-identifiable DAGs, by estimating them together with some identifiable DAGs. Lastly, our analysis also …

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Ligands For Complexation, Extraction, And Sensing Of Mercury(Ii) For Application To High-Level Waste (Hlw) At The Savannah River Site (Srs), Adenike O. Fasiku Nov 2021

Ligands For Complexation, Extraction, And Sensing Of Mercury(Ii) For Application To High-Level Waste (Hlw) At The Savannah River Site (Srs), Adenike O. Fasiku

FIU Electronic Theses and Dissertations

Mercury (Hg) separation and sensing is of high significance due to Hg(II) environmental mobility and toxicity. Furthermore, the use of Hg in nuclear applications has resulted in its accumulation in several DOE sites, such as in Oak Ridge and Savannah River reservations. Organic mercury species have been found in low activity waste (LAW) streams resulting from high-level waste (HLW) processing at the Savannah River Site (SRS), therefore posing a threat to humans and the environment. Mercury, being a soft Lewis acid, has a strong affinity for softer Lewis bases, such as S- or N-donor ligands. Therefore, we focus on …

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Predicting The Adoption Of Password Managers: A Tale Of Two Samples, Shelia Kennison, D. Eric Chan-Tin Nov 2021

Predicting The Adoption Of Password Managers: A Tale Of Two Samples, Shelia Kennison, D. Eric Chan-Tin

Computer Science: Faculty Publications and Other Works

Using weak passwords and re-using passwords can make one vulnerable to cybersecurity breaches. Cybersecurity experts recommend the adoption of password managers (PMs), as they generate and store strong passwords for all accounts. Prior research has shown that few people adopt PMs. Our research examined PM adoption in a sample of 221 undergraduates from psychology courses and a sample of 278 MTurk workers. We hypothesized that PM adoption could be predicted using a small set of user characteristics (i.e., gender, age, Big Five personality traits, number of devices used, frequency of using social media, and cybersecurity knowledge). The results showed that …

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A Quantitative Evaluation Of Global, Rule-Based Explanations Of Post-Hoc, Model Agnostic Methods, Giulia Vilone, Luca Longo Nov 2021

A Quantitative Evaluation Of Global, Rule-Based Explanations Of Post-Hoc, Model Agnostic Methods, Giulia Vilone, Luca Longo

Articles

Understanding the inferences of data-driven, machine-learned models can be seen as a process that discloses the relationships between their input and output. These relationships consist and can be represented as a set of inference rules. However, the models usually do not explicit these rules to their end-users who, subsequently, perceive them as black-boxes and might not trust their predictions. Therefore, scholars have proposed several methods for extracting rules from data-driven machine-learned models to explain their logic. However, limited work exists on the evaluation and comparison of these methods. This study proposes a novel comparative approach to evaluate and compare the …

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Hydrological Feedbacks On Peatland Ch4 Emission Under Warming And Elevated Co2: A Modeling Study, Fenghui Yuan, Yihui Wang, Daniel M. Ricciuto, Xiaoying Shi, Fengming Yuan, Thomas Brehme, Scott Bridgham, Jason Keller, Jeffrey M. Warren, Natalie A. Griffiths, Stephen D. Sebestyen, Paul J. Hanson, Peter E. Thornton, Xiaofeng Xu Nov 2021

Hydrological Feedbacks On Peatland Ch4 Emission Under Warming And Elevated Co2: A Modeling Study, Fenghui Yuan, Yihui Wang, Daniel M. Ricciuto, Xiaoying Shi, Fengming Yuan, Thomas Brehme, Scott Bridgham, Jason Keller, Jeffrey M. Warren, Natalie A. Griffiths, Stephen D. Sebestyen, Paul J. Hanson, Peter E. Thornton, Xiaofeng Xu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatland carbon cycling is critical for the land–atmosphere exchange of greenhouse gases, particularly under changing environments. Warming and elevated atmospheric carbon dioxide (eCO2) concentrations directly enhance peatland methane (CH4) emission, and indirectly affect CH4 processes by altering hydrological conditions. An ecosystem model ELM-SPRUCE, the land model of the E3SM model, was used to understand the hydrological feedback mechanisms on CH4 emission in a temperate peatland under a warming gradient and eCO2 treatments. We found that the water table level was a critical regulator of hydrological feedbacks that affect peatland CH4 dynamics; the …

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Evaluation And Utilization Of A Tall Fescue Germplasm Collection At Pergamino Inta, Argentina, B. S. Rosso, E. M. Pagano, P. Rimieri Nov 2021

Evaluation And Utilization Of A Tall Fescue Germplasm Collection At Pergamino Inta, Argentina, B. S. Rosso, E. M. Pagano, P. Rimieri

IGC Proceedings (1993-2023)

One hundred and fifty four accessions of tall fescue (Festuca arundinacea Schreb.) representing different types grown around the world were evaluated at Pergamino Inta Experimental Station. A multivariate analysis was carried out to evaluate individual and group variations. Three principal components (PCs) explained 70 % of the variation. Cluster analysis (Ward method) allowed the identification of 7 groups of populations. Plants from the most promising populations were selected in order to form a new breeding gene pool. The main objective of this study is to develop a new cultivar with improved winter herbage yield. Selected genotypes were mostly of …

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Effects Of Selection On Morphological Characteristics In Setaria Sphacelata (Schumach.) Moss, Liana Jank, Kenneth H. Quesenberry, P. Mislevy Nov 2021

Effects Of Selection On Morphological Characteristics In Setaria Sphacelata (Schumach.) Moss, Liana Jank, Kenneth H. Quesenberry, P. Mislevy

IGC Proceedings (1993-2023)

Cattle production in Florida is limited by the lack of available warm-season forages adapted to the cool winters of the region. Setaria (S. sphacelata) has demonstrated green growth during cool conditions in subtropical climates around the world, and has the potential to fill this niche in cattle production in Florida. Four populations were selected in Gainesville and Ona, Florida: two cycles of selection for increased head number, one cycle for increased leaf width and one cycle for grazing tolerance. The objectives of this research were to compare these populations morphologically to determine changes due to selection. Selection for …

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Correlated Evolution Of Distinct Signals Associated With Increased Social Selection In Female White-Shouldered Fairywrens, John Anthony Jones, Karan J. Odom, Ian R. Hoppe, Doka Nason, Serena Ketaloya, Jordan Karubian Nov 2021

Correlated Evolution Of Distinct Signals Associated With Increased Social Selection In Female White-Shouldered Fairywrens, John Anthony Jones, Karan J. Odom, Ian R. Hoppe, Doka Nason, Serena Ketaloya, Jordan Karubian

School of Natural Resources: Faculty Publications

Conspicuous female signals have recently received substantial scientific attention, but it remains unclear if their evolution is the result of selection acting on females independently of males or if mutual selection facilitates female change. Species that express female, but not male, phenotypic variation among populations represents a useful opportunity to address this knowledge gap. White-shouldered fairywrens (Malurus alboscapulatus) are tropical songbirds with a well-resolved phylogeny where female, but not male, coloration varies allopatrically across subspecies. We explored how four distinct signaling modalities, each putatively associated with increased social selection, are expressed in two populations that vary in competitive pressure on …

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Comparative Study Of New And Traditional Estimators Of A New Lifetime Model, Sandeep Kumar Maurya, Sanjay Kumar Singh, Umesh Singh Nov 2021

Comparative Study Of New And Traditional Estimators Of A New Lifetime Model, Sandeep Kumar Maurya, Sanjay Kumar Singh, Umesh Singh

Journal of Modern Applied Statistical Methods

In this article, we have studied the behavior of estimators of parameter of a new lifetime model, suggested by Maurya et al. (2016), obtained by using methods of moments, maximum likelihood, maximum product spacing, least squares, weighted least squares, percentile, Cramer-von-Mises, Anderson-Darling and Right-tailed Anderson-Darling. Comparison of the estimators has been done on the basis of their mean square errors, biases, absolute and maximum absolute differences between empirical and estimated distribution function and a newly proposed criterion. We have also obtained the asymptomatic confidence interval and associated coverage probability for the parameter.

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Mgrre_Pureoilscouttickets_Fee_1_21127027830000, Mgrre Nov 2021

Mgrre_Pureoilscouttickets_Fee_1_21127027830000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.

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The Economics Of Residential Solar And Battery Storage: Analyzing The Impact Of The Joint Iou Proposal For Net Metering 3.0 In California, Candace E. Ybarra, Prashanth U. Nyer, John B. Broughton, Thomas A. Turk Nov 2021

The Economics Of Residential Solar And Battery Storage: Analyzing The Impact Of The Joint Iou Proposal For Net Metering 3.0 In California, Candace E. Ybarra, Prashanth U. Nyer, John B. Broughton, Thomas A. Turk

Business Faculty Articles and Research

The California Public Utilities Commission (CPUC) is currently deciding on the structure of the next net metering program, which will determine how customers who install solar panels (and battery storage) under this new program will be compensated for excess energy that they export to the grid, and the additional fees that these solar customers will have to pay. The major investor-owned utility (IOU) companies in the state and some legislators have argued that the current net metering programs are far too generous to the customers and that they create an inequity by favoring the wealthy and causing a cost shift …

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Approved Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed Sites Field Sampling Plan (Fsp) Package #6: Ur‐05, Ur‐27, Ur‐28, Ur‐29, Ur‐30, And Ur‐34, Mike Mcanulty Nov 2021

Approved Final Butte Priority Soils Operable Unit (Bpsou) Unreclaimed Sites Field Sampling Plan (Fsp) Package #6: Ur‐05, Ur‐27, Ur‐28, Ur‐29, Ur‐30, And Ur‐34, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

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Investigation Of Immobilized Enzymes In Confined Environment Of Mesoporous Host Matrices, Xiaoliang Wang Nov 2021

Investigation Of Immobilized Enzymes In Confined Environment Of Mesoporous Host Matrices, Xiaoliang Wang

USF Tampa Graduate Theses and Dissertations

Enzyme immobilization in metal-organic frameworks (MOFs) as a promising strategy, is attracting the interest of scientists from different disciplines with the expansion of MOF’s development. Different from other traditional host materials, their unique strengths of high surface areas, large yet adjustable pore sizes, functionalizable pore walls, and diverse architectures make MOFs an ideal platform to investigate hosted enzymes, which is critical to the industrial and commercial process. In addition to the protective function of MOFs, the extensive roles of MOFs in the enzyme immobilization are being well-explored by making full use of their remarkable properties like well-defined structure, high porosity, …

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Searches For Continuous Gravitational Waves From Young Supernova Remnants In The Early Third Observing Run Of Advanced Ligo And Virgo, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales Nov 2021

Searches For Continuous Gravitational Waves From Young Supernova Remnants In The Early Third Observing Run Of Advanced Ligo And Virgo, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present results of three wide-band directed searches for continuous gravitational waves from 15 young supernova remnants in the first half of the third Advanced LIGO and Virgo observing run. We use three search pipelines with distinct signal models and methods of identifying noise artifacts. Without ephemerides of these sources, the searches are conducted over a fRequency band spanning from 10 to 2 kHz. We find no evidence of continuous gravitational radiation from these sources. We set upper limits on the intrinsic signal strain at 95% confidence level in sample subbands, estimate the sensitivity in the full band, and derive …

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Volumetric Extrusive Rates Of Silicic Supereruptions From The Afro-Arabian Large Igneous Province, Jennifer E. Thines, Ingrid A. Ukstins, Corey Wall, Mark Schmitz Nov 2021

Volumetric Extrusive Rates Of Silicic Supereruptions From The Afro-Arabian Large Igneous Province, Jennifer E. Thines, Ingrid A. Ukstins, Corey Wall, Mark Schmitz

Geosciences Faculty Publications and Presentations

The main phase of silicic volcanism from the Afro-Arabian large igneous province preserves some of the largest volcanic eruptions on Earth, with six units totaling >8,600 km3 dense rock equivalent (DRE). The large volumes of rapidly emplaced individual eruptions present a case study for examining the tempo of voluminous silicic magma generation and emplacement. Here were report high-precision 206Pb/238U zircon ages and show that the largest sequentially dated eruptions occurred within 48 ± 34 kyr (29.755 ± 0.023 Ma to 29.707 ± 0.025 Ma), yielding the highest known long-term volumetric extrusive rate of silicic volcanism on …

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From Mdp To Alphazero, David Robert Sewell Nov 2021

From Mdp To Alphazero, David Robert Sewell

Dissertations and Theses

In this paper I will explain the AlphaGo family of algorithms starting from first principles and requiring little previous knowledge from the reader. The focus will be upon one of the more recent versions AlphaZero but I hope to explain the core principles that allowed these algorithms to be so successful. I will generally refer to AlphaZero as theses [sic] core set of principles and will make it clear when I am referring to a specific algorithm of the AlphaGo family. AlphaZero in short combines Monte Carlo Tree Search (MCTS) with Deep learning and self-play. We will see how these …

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Evaluation Of Leucaena Genotypes, F. B. Sousa, M. R. A. Araujo, J. A. Araujo Filho, J. Sousa Neto Nov 2021

Evaluation Of Leucaena Genotypes, F. B. Sousa, M. R. A. Araujo, J. A. Araujo Filho, J. Sousa Neto

IGC Proceedings (1993-2023)

The objectives of this study were to evaluate the leucaena (Leucaena leucocephala) performance and to select the best genotypes, based on yield,.stability parameters, and quality parameters. Annual leucaena yields were obtained by cuts over the rainy and dry seasons. A combined analysis of variance for yield, and quality parameters was performed. Also stability parameters and coeficients of determination were estimated. The combined ANOVA for edible dry matter yield and for acid detergent fiber, and digestibility revealed a significant difference for genotypes, environments, genotypes x environments, row spacings, cutting frequencies, and cutting heights, Six genotypes of leucaena were selected …

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Genotype-Environment Interaction For Forage Yield Of Vetch (Vicia Sativa L.) In Mediterranean Environments, G. Pacucci, C. Troccoli Nov 2021

Genotype-Environment Interaction For Forage Yield Of Vetch (Vicia Sativa L.) In Mediterranean Environments, G. Pacucci, C. Troccoli

IGC Proceedings (1993-2023)

Genotype x environment (GE) interactions limit the effectiveness of selection when selection is based only on mean yields. The objective of this study was to evaluate the amount of GE interaction for vetch forage yield in some environments of Southern Italy, and to analyze some stability parameters that can be useful in the selection of genotypes adapted to Mediterranean environmental conditions. Eleven vetch genotypes were grown in a total of 16 environments in Southern Italy. The combined analysis of variance for forage yield showed that the environment, genotype and GE interaction terms were significant at 0.01 level, suggesting a broad …

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Initial Biomass Production And Soluble Carbohydrate Partitioning Of Contrasting Elephantgrass Genotypes, L. P. Passos, M. C. Vidigal, R. S. Verneque Nov 2021

Initial Biomass Production And Soluble Carbohydrate Partitioning Of Contrasting Elephantgrass Genotypes, L. P. Passos, M. C. Vidigal, R. S. Verneque

IGC Proceedings (1993-2023)

The initial growth and soluble carbohydrate (SC) partitioning were examined in the following classes of elephantgrass (Pennisetum purpureum Schum.) genotypes: Dwarf (Anão, Mott and Roxo); Cameroon (Cameroon, Cameroon Piracicaba and Vruckwona); Embrapa hybrids (CNPGL F27-5 and Pioneiro); Interspecific hybrids (Hexaploide 201, Mercker X 23-A and Napier X 23-A; Mercker (Mercker Comum, Mercker Pinda and Teresópolis); and Napier (E.C. Itapemirim, Mineiro and Napier). After a 60-day growing period, total, leaf, stem and root FW and DW and stem, stem base, leaf and root SC content were determined. Cameroon-class cultivars showed the highest leaf and stem DW and whole stem SC …

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Evaluation Of Guineagrass (Panicum Maximum Jacq) Hybrids In Brazil, Liana Jank, Cacilda B. Do Valle, J. De Carvalho, S. Calixto Nov 2021

Evaluation Of Guineagrass (Panicum Maximum Jacq) Hybrids In Brazil, Liana Jank, Cacilda B. Do Valle, J. De Carvalho, S. Calixto

IGC Proceedings (1993-2023)

Guineagrass (Panicum maximum Jacq.) is responsible for a high percentage of cattle finishing and milk production in Brazil, but presents problems of pasture degradability due to high soil fertility requirements and uneven production distribution. In order to search for new varieties to reduce these problems, over four hundred apomictic accessions of guineagrass and several sexual plants were introduced to Brazil in 1982. Agronomic evaluation took place at the National Beef Cattle Research Center of the Brazilian Agricultural Research Corporation (Embrapa Beef Cattle), in Campo Grande, MS, Brazil. Breeding of the apomictic species began in 1990 using sexual x apomictic …

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The Effect Of Climate Change On The Water Reserve In Wadi Of Hadhramout, Jamal A. Abbad, Khaled S. Bawahidi, Mohamed A. Bawadi Nov 2021

The Effect Of Climate Change On The Water Reserve In Wadi Of Hadhramout, Jamal A. Abbad, Khaled S. Bawahidi, Mohamed A. Bawadi

Hadhramout University Journal of Natural & Applied Sciences

This research aims to study the reality of the impact of climate change on water resources in Wadi (valley) of Hadhramout, as this region is exposed to the impacts of climate change on groundwater resources, through the effects on rainfall and surface water supplies. Climate change is a global phenomenon affecting water resources, so it is necessary to study its impact, specifically on the water reserve in wadi of Hadhramout. from this point of view this problem was taken into account in our study in terms of the possibility of maintaining the balance of water reserves in the study area. …

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Proving The Possibility Of The Calculation Of The Madeluag Constant For The Sodium Chloride Crystal Using A Limited Number Of The Terms Of The Series Giving The Expression Of This Constant, Saleh Saeed Barbaid Nov 2021

Proving The Possibility Of The Calculation Of The Madeluag Constant For The Sodium Chloride Crystal Using A Limited Number Of The Terms Of The Series Giving The Expression Of This Constant, Saleh Saeed Barbaid

Hadhramout University Journal of Natural & Applied Sciences

In this research, after referring to the basic assumption of the theory of the binding energy of the ionic crystals, we explained the Madelung constant and then, we show how the method of the neutral electric groups introduced by Evjen facilitates the convergent of the series showing the Madelung constant. Then, afterwards, we reviewed the principal points of the crystalline structure of the sodium chloride which crystallizes in a cubic faces centred lattice; showing that the apparition 0f 27 ions in each unit cell of its space lattice; afterward we calculate different values of the Madelung constant, showing how we …

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Investigating Thermodynamics And Kinetics Of Methylene Blue And Eriochrome Black-T Adsorption On Activated Carbon Prepared From Coconut Husk, Abdul Rahman Wahoud, Lotfi Abdul Samed Bawazer Nov 2021

Investigating Thermodynamics And Kinetics Of Methylene Blue And Eriochrome Black-T Adsorption On Activated Carbon Prepared From Coconut Husk, Abdul Rahman Wahoud, Lotfi Abdul Samed Bawazer

Hadhramout University Journal of Natural & Applied Sciences

In this research, the adsorption process was studied for methylene blue eriochrome black-T from aqueous solutions on the surface of activated carbon prepared from coconut husk by chemical activation with potassium hydroxide. The results show that the adsorption isotherm for methylene blue follows the Langmuir model while it follows the Freundlich model and the maximum adsorption capacity was 909 mg/g for methylene blue and 262 mg/g for eriochrome black-T. The equilibrium contact time reached in about 90 minutes at lower concentrations and 120 minutes at higher concentrations. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equations were selected to follow …

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Fifth And Eleventh-Order Iterative Methods For Roots Of Nonlinear Equations, Hassan Mohammed Bawazir Nov 2021

Fifth And Eleventh-Order Iterative Methods For Roots Of Nonlinear Equations, Hassan Mohammed Bawazir

Hadhramout University Journal of Natural & Applied Sciences

In this work, two iterative methods, based on Newton’s method, to obtain the numerical solutions of nonlinear equations have been constructed. We proved that our methods converge in fifth and eleventh orders. Analytical investigation has been established to show that our schemes have higher efficiency indexes than some recent methods. Numerical examples are experimented to investigate the performance of the proposed schemes. Moreover, the theoretical order of convergence is verified in the experiment work.

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On N Satisfying, N Dividing Φ(N)Σ(N)+1, Hussain Abdulkader Al-Aidroos Nov 2021

On N Satisfying, N Dividing Φ(N)Σ(N)+1, Hussain Abdulkader Al-Aidroos

Hadhramout University Journal of Natural & Applied Sciences

Let denotes the sum of the positive divisors of the positive integer and be the Euler’s totient function([1],page25). Cleary, divides if is a prime. Then, the question is there a composite that divides ? Considering this problem Yang-Gao Chen and Jin-Hui Fang [5] have proved that , where as usual is the number of distinct prime factors of. and , .We devoted the study of this problem where we prove that every in is odd and that , from which it follows that for any composite in the least prime factors is . Also, we obtained lower bounds for and …

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Assessment Of Temperature Change In Mukalla City In Hadhramaut Governorate And Its Impact On The Environment, Jamal Abu Bakr Abbad, Fahad Hussein Alsomahi, Nabeela Obeid Baharah, Fatima Saleh Alsaeedi Nov 2021

Assessment Of Temperature Change In Mukalla City In Hadhramaut Governorate And Its Impact On The Environment, Jamal Abu Bakr Abbad, Fahad Hussein Alsomahi, Nabeela Obeid Baharah, Fatima Saleh Alsaeedi

Hadhramout University Journal of Natural & Applied Sciences

This research is based on the inventory of data and information on daily and monthly temperatures from 2000 to 2017, where we analyzed the data obtained from NASA about the city of Mukalla for the specified period of time. Using equations, the average daily temperature was calculated from the daily temperature data multiple times equivalent to eight times a day. Monthly and annual averages were calculated using statistical methods. The results clearly show the extent of the change in the temperature rate during the study period. It is noted that there was an increase in the rate of temperature change …

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