Size Calculation Research Articles

AlzPED: Improving the predictive power and translational validity of preclinical testing of candidate therapeutics in Alzheimer’s disease animal models

AbstractBackgroundAlzPED is a publicly available database created by the National Institute on Aging to address key factors contributing to poor translation of preclinical efficacy from animal models to the clinic in Alzheimer’s disease (AD) therapy development. Specifically, AlzPED is missioned to identify critical experimental design elements and methodology missing from studies that make them susceptible to misinterpretation and reduce their reproducibility and translational value, as well as serve as a platform for reporting unpublished negative findings. AlzPED provides funding agencies with a tool for enforcement of the requirements for transparent reporting and rigorous study design. Through these capabilities, AlzPED is intended to guide the development and implementation of strategies and recommendations for standardized best practices for the rigorous preclinical testing of AD candidate therapeutics and mitigate the publication bias that favors the reporting of positive findings.MethodUsing key word‐driven literature searches published studies are acquired and curated by two experts for data on authors, funding source, AD animal models, therapeutic targets and therapeutic agents, study design, and outcome measures, prior to publication in the database. Rigor in study design is evaluated with an experimental design scorecard that summarizes the elements of experimental design reported in each study in the database.ResultAlzPED currently houses curated summaries from 917 published studies. Summaries are searchable by author, funding source, animal model, therapeutic target and therapeutic agent. At present, the database contains data on 185 animal models, 175 therapeutic targets, 804 therapeutic agents and, more than 1500 AD‐related outcome measures. Evaluation of experimental design scorecards from each study demonstrates significant under‐reporting of critical elements of methodology even in high impact factor journals and highly cited published preclinical research.ConclusionAnalysis of curated studies demonstrates serious deficiencies in reporting critical elements of methodology such as power/sample size calculation, blinding for treatment/outcomes, randomization, balancing for sex, animal genetic background and others, irrespective of journal impact factor and number of citations. These deficiencies diminish the scientific rigor, reproducibility and translational value of the preclinical studies. Thus, it is evident that a standardized set of best practices is required for successful translation of therapeutic efficacy in AD research.

Process Drive Sizing Methodology and Multi-Level Modeling Linking MATLAB® and Aspen Plus® Environment

Optimal steam process drive sizing is crucial for efficient and sustainable operation of energy-intense industries. Recent years have brought several methods assessing this problem, which differ in complexity and user-friendliness. In this paper, a novel complex method was developed and presented and its superiority over other approaches was documented on an industrial case study. Both the process-side and steam-side characteristics were analyzed to obtain correct model input data: Driven equipment performance and efficiency maps were considered, off-design and seasonal operation was studied, and steam network topology was included. Operational data processing and sizing calculations were performed in a linked MATLAB®–Aspen Plus® environment, exploiting the strong sides of both software tools. The case study aimed to replace a condensing steam turbine by a backpressure one, revealing that: 1. Simpler methods neglecting frictional pressure losses and off-design turbine operation efficiency loss undersized the drive and led to unacceptable loss of deliverable power to the process; 2. the associated process production loss amounted up to 20%; 3. existing bottlenecks in refinery steam pipelines operation were removed; however, new ones were created; and 4. the effect on the marginal steam source operation may vary seasonally. These findings accentuate the value and viability of the presented method.

Determination and modelling of density, viscosity and solubility of (R)-(-)-phenylephrine hydrochloride in methanol + ethyl acetate at (278.15–323.15) K and 0.1 MPa

For further optimizing the pipeline design of continuous crystallizer, in this research work, density, viscosity and solid-liquid equilibria (SLE) solubility of (R)-(-)-phenylephrine hydrochloride (R-PEC) in binary solvent of “methanol (MtOH) + ethyl acetate (EtAC)” were investigated at temperature T = (278.15–323.15) K under pressure p = 0.1 MPa. The results showed that experimental density and viscosity values were negatively related with temperature while the SLE solubility data had positive correlation with the experimental temperature. Moreover, density and viscosity profiles increased with the incremental molarity of R-PEC, similarly, solubility of R-PEC raised along with the mass fraction of MtOH in binary solvents. Hansen solubility parameter (HSP) was applied to investigate the solubility behavior of R-PEC in MtOH+EtAC, four selected solubility parameters could give a logical explanation on R-PEC solubility. By using Mathcad software (Version: 15), the Vogel-Tammann-Fulcher (VTF) equation was employed for the description of density as well as viscosity values. Values of average relative deviation (ARD), multi-correlation coefficient (R2) and root-mean square deviation (RMSD) between experimental data and predicted data showed that VTF equation could provide satisfactory correlations with the experimental data. Besides, solubility values of R-PEHC in selected binary solvent were correlated with three activity coefficient models including Wilson, NRTL (Non-Random Two Liquids) and UNIQUAC (Universal Quasi–Chemical) model by using Mathcad software, the UNIQUAC model were more suitable for correlation with experimental solubility than others in terms of ARD and RMSD. Furthermore, based on the experimental solubility results and regression parameters of UNIQUAC model, thermodynamic properties of mixing and dissolution process were discussed in this work, the results showed that the both processes of R-PEHC in MtOH+EtAC were always spontaneous and entropy driven, the mixing process and part of dissolution process (R-PEHC in MtOH + EtAC at T ≤ 303.15 K) were exothermic. Experimental densities, viscosities, solubility as well as selected models would be very helpful for optimizing the pipeline design (including material selection, size calculation and so on) of continuous crystallizer.

Abstract 6141: Role of aldehyde dehydrogenase 1B1 in colon carcinogenesis in a newly developed mouse model

Abstract Introduction: Aldehyde dehydrogenases (ALDH), particularly ALDH1B1 has been shown to have increased expression in both human and APCMin mice colorectal tumors. Studies have proposed the use of ALDH1B1 as a potential novel human colorectal tumor marker. Previous in vitro studies have shown that ALDH1B1 plays a critical role in colon carcinogenesis. The goal of this study is to understand the in vivo role of ALDH1B1 in colon carcinogenesis using a newly developed mouse model, APCMinAldh1b1−/− mice, through characterization of its phenotype in tumor growth and development, and elucidating the underlying potential molecular mechanisms. Methods: We generated APCMinAldh1b1−/-. At 12-14 weeks old, the experimental group APCMinAldh1b1−/- (n=6) and control group APCMinAldh1b1+/+ (n=7) were euthanized. Tumor counts, size and burden for each intestinal segments were recorded. H&E staining was performed and observed for tumor types and counts. Immunohistochemistry using the markers Ki-67 (proliferation), Cleave Caspase 3 (apoptosis), KRT20 (differentiation) were done in colon. IHC of retinoic acid binding proteins (anti-CRBP2 and anti-FABP5) were also performed Results: The experimental group had shown significantly higher total average intestinal tumor burden (6.8 fold) (p=0.0007) and total average tumor counts observed (3.6 fold) (p=0.02). In the colon, there was a 3.5-fold increase in average tumor burden (p=0.017) with a 2.7-fold increase in average tumor size (p=0.025)in the experimental group. We also noticed a trend of increased average tumor counts observed in the colon of the experimental group although statistically insignificant. Average tumor counts of ileum observed was 9-fold higher in experimental group with only 1 mice from control group showed observable small tumor growth which did not meet criteria for tumor size and tumor burden calculation. There were no significant differences in observable tumor counts, tumor size and tumor burden in jejunum. Histologically, all tumors were pedunculated adenocarcinomas. Many unobservable small tumors less than 1mm width and length were seen in the H&E of both ileum and jejunum in the experimental and control group. In the control group, there was less observable tumors compared to the experimental group although the tumor counts on H&E in both groups showed no major differences. This indicates that the tumor size in the experimental group was larger than the control group. On the contrary, average tumor counts of colon in H&E were lower compared to tumor counts observed in both control and experimental groups, indicating low number of small unobservable tumors in colon. Although the tumor counts of colon on H&E and observation between the two groups were statistically insignificant, we noticed a pattern of increased tumor counts in the experimental group suggesting a potential increase in tumor incidence. Immunohistochemical staining of colon is ongoing. Conclusion: ALDH1B1 reduced tumor growth rate in the ileum, and reduced tumor size in the colon suggesting its role in tumor promotion and progression. A larger number of experimental and control group is required to establish its potentially tumor-initiating role in the colon. Further characterization of ALDH1B1 in colon carcinogenesis is ongoing. We are also elucidating the role and regulation of retinoic acid signaling by ALDH1B1 in colorectal tumor growth. Citation Format: Wan Ying Tan, David. J. Orlicky, Ying Chen, Yatrik M. Shah, David C. Thompson, Vasilis Vasiliou. Role of aldehyde dehydrogenase 1B1 in colon carcinogenesis in a newly developed mouse model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6141.

Cross-Linguistic Perceptual Categorization of the Three Corner Vowels: Effects of Listener Language and Talker Age.

The present study examined the center and size of naïve adult listeners' vowel perceptual space (VPS) in relation to listener language (LL) and talker age (TA). Adult listeners of three different first languages, American English, Greek, and Korean, categorized and rated the goodness of different vowels produced by 2-year-olds and 5-year-olds and adult speakers of those languages, and speakers of Cantonese and Japanese. The center (i.e., mean first and second formant frequencies (F1 and F2)) and size (i.e., area in the F1/F2 space) of VPSs that were categorized either into /a/, /i/, or /u/ were calculated for each LL and TA group. All center and size calculations were weighted by the goodness rating of each stimulus. The F1 and F2 values of the vowel category (VC) centers differed significantly by LL and TA. These effects were qualitatively different for the three vowel categories: English listeners had different /a/ and /u/ centers than Greek and Korean listeners. The size of VPSs did not differ significantly by LL, but did differ by TA and VCs: Greek and Korean listeners had larger vowel spaces when perceiving vowels produced by 2-year-olds than by 5-year-olds or adults, and English listeners had larger vowel spaces for /a/ than /i/ or /u/. Findings indicate that vowel perceptual categories of listeners varied by the nature of their native vowel system, and were sensitive to TA.

Discoveries and Dilemmas—Excavating the Serridge Engine House (c1790)

This article is an initial interpretation of the features revealed by the South Gloucestershire Mines Research Group’s documentary research and archaeological investigations of the Serridge Newcomen Engine. The site is located in the Parish of Westerleigh in part of the Coalpit Heath Coal Basin in South Gloucestershire. Excavations have confirmed the location of the engine house constructed c1790 and the presence of significant remains. Two storeys of the engine house and several related features have been uncovered and conserved with underground access maintained. These features and the interpretation of some of the anomalies they present form the basis of this account. Consideration is given to the function of the multiple beams, calculations of the cylinder size and principle beam length, the number of storeys, consideration of a second shaft as a possible reservoir, the purpose of a circular tunnel through the engine house and the general internal layout.

Calculation of the ideal plot size for experiments using eucalyptus

An adequate experimental planning depends on several factors, such as homogeneity of the area and experimental unity, number of repetition and plot size. The adoption of an ideal plot size reduces the experimental error and, consequently, maximizes the information obtained in an experiment. Thus, the aim of the present study was to calculate the optimal plot size of eucalyptus culture in a greenhouse, in order to optimize labor and costs in the cultivation process of this economically important culture. To calculate the optimal plot size, several simulations were performed using the modified maximum curvature method. Throughout the experimental period, clonal seedlings of the Eurograndis hybrid were used and evaluated for height (H), stem diameter at the base (DB), chlorophyll content in old leaves (Chlor V) and new leaves (Chlor N) at 30, 60, 90 and 120 days after seedling transplantation. After 120 days, the seedlings were collected to determine the dry mass of the aerial part (DMAP) and the root system (DMRS). Results indicated that the optimal recommended plot size for eucalyptus, in a greenhouse, were 6 plants per plot.

Lead Exposure on Blood Pressure and Lipid Parameters Alteration among People around Bus Terminal in Yogyakarta

Lead is generated as residual progress of vehicle or factory process. The excessive amount of lead has several impacts on human health system namely on cardiovascular, respiratory, endocrine and metabolic system through damaging enzymatic process and Reactive Oxygen Species (ROS). The aim of this study is to search the correlation of lead exposure on blood pressure and lipid parameters alteration among people around bus terminal in Yogyakarta. This study is a cross sectional research design. According to calculation of sample size, 71 respondents had fulfilled the inclusion criteria such as: Agree to be respondents, 6 hours fasting prior to take data, age >18 years old and had history of staying nearby bus terminal for more than one year. The variables divided into two, independent variable is lead exposure and dependent variables are SBP and DBP meanwhile lipid parameters such as LDL, HDL and TG. Those variables were analyzed by linier regression. Based on linier regression was obtained that SBP (p value 0.004, r 0.33 and R square 0.11), DBP (p value 0.001 r 0.37 and R square 0.138), LDL (p value 0.002 r 0.35 and R square 0.128), HDL (p value 0.001, r 0.37 and R square 0.139) and TG (p value 0,002, r 0.36 and R square 0.130). The result of study was found that lead exposure contributed on blood pressure and lipid parameters alteration among people around bus terminal in Yogyakarta.

Metodologías cuantitativas: Cálculo del tamaño de muestra con STATA y R

El cálculo de tamaño de muestra es un aspecto esencial del diseño de estudios cuantitativos. Un adecuado tamaño de muestra nos permite determinar cuál es la mínima cantidad de participantes necesarios para probar nuestra hipótesis de interés. De esta manera, podemos reducir costos, maximizar el uso de nuestros recursos de investigación y garantizar la factibilidad del estudio. Contradictoriamente, a pesar de su relevancia muy pocos investigadores dominan esta habilidad. Esta revisión tiene por objeto revisar los conceptos básicos para realizar un cálculo de tamaño de muestra y compartir códigos de Stata y R específicamente diseñados para facilitar estos cálculos.

TFisher: A powerful truncation and weighting procedure for combining $p$-values

The $p$-value combination approach is an important statistical strategy for testing global hypotheses with broad applications in signal detection, meta-analysis, data integration, etc. In this paper we extend the classic Fisher’s combination method to a unified family of statistics, called TFisher, which allows a general truncation-and-weighting scheme of input $p$-values. TFisher can significantly improve statistical power over the Fisher and related truncation-only methods for detecting both rare and dense “signals.” To address wide applications, analytical calculations for TFisher’s size and power are deduced under any two continuous distributions in the null and the alternative hypotheses. The corresponding omnibus test (oTFisher) and its size calculation are also provided for data-adaptive analysis. We study the asymptotic optimal parameters of truncation and weighting based on Bahadur efficiency (BE). A new asymptotic measure, called the asymptotic power efficiency (APE), is also proposed for better reflecting the statistics’ performance in real data analysis. Interestingly, under the Gaussian mixture model in the signal detection problem, both BE and APE indicate that the soft-thresholding scheme is the best, the truncation and weighting parameters should be equal. By simulations of various signal patterns, we systematically compare the power of statistics within TFisher family as well as some rare-signal-optimal tests. We illustrate the use of TFisher in an exome-sequencing analysis for detecting novel genes of amyotrophic lateral sclerosis. Relevant computation has been implemented into an R package TFisher published on the Comprehensive R Archive Network to cater for applications.

A non-inferiority test and sample size determination for comparing two predictive values of diagnostic tests

Positive and negative predictive values describe the clinical performance of the diagnostic test when it is applied to a cohort of individuals. Testing non-inferiority of predictive values may be adequate in some cases due to the simplicity of the examination and the invasiveness of the test, but no non-inferiority test for predictive values has been proposed yet. In this study, we propose a non-inferiority test that investigates the non-inferiority of predictive values in paired designs, and formulae for the calculation of sample size to execute the non-inferiority test of two predictive values. Simulation studies showed that the proposed non-inferiority test is useful for comparing two predictive values in clinical trials.

Периоперационная ишемия neorectum’a. Экспериментальная модель

Objective. To experimentally determine and analyze the role of perioperative tissue tension in the intestinal area brought down to the proper topographic and anatomical position (neorectum) and its vascularization impairments during anorectoplasty. Materials and methods. This experiment performed on laboratory rats consisted of 3 parts: clinical (creation of an operation model and assessment of clinical parameters in the early postoperative period); morphological (histological examination of biopsy specimens taken from the surgical area); and laboratory (measurement of tissue hypoxia markers (including vascular endothelial growth factor-C (VEGF-C) and hypoxia-induced factor 1-alpha (HIF-1-alpha)) in serum and intestinal homogenate using enzyme-linked immunosorbent assay (ELISA) (specimens were collected 3 days postoperatively). Forty laboratory rats weighing from 370 to 550 g (mean weight 482 g) were divided into four equal groups: group I – ‘impaired neorectal vascularization;’ group II – ‘neorectal tension;’ group III – ‘rectal replantation;’ and the control group. During the first stage of the experiment (3 days), we assessed overall condition of the animals, number of stools, type of defecation, and pain severity. The animals received no treatment in the postoperative period. On day 3, all rats were euthanized. Tissue specimens were collected from the neorectum to evaluate its morphological characteristics and to produce intestinal homogenate for subsequent ELISA. Blood specimens were obtained by puncturing the left ventricle and then centrifuged at 3000g for 15 minutes. Blood supernatants and neorectum tissues were stored at -80°C for maximum 1 month before testing. Intestinal tissue samples for histological examination were stored in a 10% formalin solution. The levels of hypoxia biomarkers were measured in serum and intestinal homogenate using the Stat Fax 2100. Data analysis was conducted using the SPSS software (with no preliminary calculation of the sample size). We used the Mann–Whitney U-test [H.B.Mann, D.R.Whitney] and Kruskal–Wallis test [W.Kruskall, W.A.Walles]. The differences were considered significant at р < 0.05. Results. The most common morphological changes were caused by impaired vascularization of the rectum. We have found a significant increase (p < 0.001) in the levels of hypoxia markers in intestinal homogenates in all three experimental compared to controls. However, there was no significant difference in the levels of these markers between the experimental groups. The defecation process was abnormal in rats from groups I and II. Conclusion. In anorectoplasty, excessive mobilization of the rectum with its improper vascularization and formation of the anus under conditions of intestinal tissue tension lead to perioperative neorectal ischemia. This experiment should be continued to evaluate long-term results. The proposed models of perioperative neorectal ischemia can be used to analyze the role of many factors that can potentially affect the outcome of anorectal malformation correction. In the future, this problem may be investigated in clinical studies. Key words: anorectal malformations, perioperative ischemia, neorectum, tension, devascularization

ВИКОРИСТАННЯ МОЖЛИВОСТЕЙ МОВИ ПРОГРАМУВАННЯ ТА СЕРЕДОВИЩА R У ПСИХОЛОГІЧНИХ ДОСЛІДЖЕННЯХ: Т’ЮТОРІАЛ З БАЗОВИХ МЕТОДІВ

The article belongs to a special modern genre of scholar publications, so-called tutorials – articles devoted to the application of the latest methods of design, modeling or analysis in an accessible format in order to disseminate best practices. The article acquaints Ukrainian psychologists with the basics of using the R programming language to the analysis of empirical research data. The article discusses the current state of world psychology in connection with the Crisis of Confidence, which arose due to the low reproducibility of empirical research. This problem is caused by poor quality of psychological measurement tools, insufficient attention to adequate sample planning, typical statistical hypothesis testing practices, and so-called “questionable research practices.” The tutorial demonstrates methods for determining the sample size depending on the expected magnitude of the effect size and desired statistical power, performing basic variable transformations and statistical analysis of psychological research data using language and environment R. The tutorial presents minimal system of R functions required to carry out: modern analysis of reliability of measurement scales, sample size calculation, point and interval estimation of effect size for four the most widespread in psychology designs for the analysis of two variables’ interdependence. These typical problems include finding the differences between the means and variances in two or more samples, correlations between continuous and categorical variables. Practical information on data preparation, import, basic transformations, and application of basic statistical methods in the cloud version of RStudio is provided.

Гидроксид титана как прекурсор для получения функциональных материалов

It was found that finely ground powders can polymorphically transform into other nonequilibrium crystalline phases in the study of phase transformations of X-ray amorphous titanium hydroxide (TH) in the process of mechanical activation in the presence of additives in the form of zinc compounds. Judging by the increase in the intensity of the peaks in the diffraction patterns, it can be stated that amorphous phase crystallizes in the form of anatase and brookite as a result of high-energy exposure. It is shown that the lower the degree of hydration of titanium hydroxide, the efficiency of the mechanical effect of the additive on phase transformations is higher. The following trend for the effect of the introduced modifier is observed — ZnSO4·7 H2O > > Zn(NO3)2·6 H2O > ZnO. This dependence is due to the combination of physical and chemical transformations of the material located in the field of intense mechanical influence, confirmed by data on the calculation of crystallite size and microstrains. The conversion of excess mechanical energy into thermal energy initiates chemical processes with the formation of solid titanium-zinc solutions, which accelerate the restructuring of the crystalline structure upon calcination of the modified titanium hydroxide according to the scheme: anatase-brookite-rutile. The obtained results have the prospects of practical application in the production of the so-called “rutile” nuclei used in the industrial production of titanium dioxide for various purposes.

Anatomy of the Xáltipan ignimbrite at Los Humeros Volcanic Complex; the largest eruption of the Trans-Mexican Volcanic Belt

The Xáltipan ignimbrite (ca. 290 km3 DRE) represents the major explosive event from Los Humeros Volcanic Complex (LHVC) that can be ranked as the largest caldera-forming eruption of the Trans-Mexican Volcanic Belt (TMVB). This eruption marked the onset of an explosive period of LHVC producing the collapse of the main Los Humeros caldera at 164 ± 4.2 ka. This paper provides a detailed characterization of the Xáltipan ignimbrite anatomy and eruptive chronology that records a multi-phase, single eruption. This eruption resulted in more complex architecture and lithofacies variations of the ignimbrite than previously reported. To support these findings, we present two representative composite Xáltipan stratigraphic columns based on two regional reference sections, together with a welding lithofacies map, digital mapping, energy line projections, geologic sections and high-resolution petrophysical characterization (micro-CT, He-pycnometry). Additionally, we have reevaluated the magnitude (DRE volume), and the total erupted mass of the deposit by taking into account critical primary and post-emplacement processes such as lithic concentration, welding grade, and bulk loss due to erosion. The internal architecture of the Xáltipan ignimbrite is composed of two flow units and two pumice fallout deposits (a basal one and an intercalated layer), which formed as a result of a voluminous and sequential eruption that can be resumed in four eruptive phases. The initial stage of the eruption produced a basal pumice fallout (BPF) (phase 1) derived from a buoyant plume that eventually collapsed, generating pyroclastic density current (PDC) deposits with intra-ignimbrite pumice fallout beds. This event was followed by the climactic, caldera-forming, boiling over-type eruptive phase (phase 2) that generated voluminous PDCs of the lower flow unit (LFU). As the eruption waned, a brief eruptive hiatus occurred, immediately followed by a second explosive event in the western rim of the caldera with a boiling-over type eruptive column depositing a discrete pumice fallout layer (IPF) (phase 3), which later collapsed depositing less voluminous PDC (UFU) in the western flank of the Los Humeros caldera (phase 4). The anatomy of the deposits shows that the Xáltipan ignimbrite was emplaced in different behaviors: radially in the proximal parts and channelized and confined in the distal parts, showing significant welding variations that range from non-to-highly welded conditions (welding ranks I-VI) controlled mainly by the paleotopography. The size calculations indicate that the deposits have an aerial extent of ca. 4600 km2, an ejected bulk volume of ca. 330 km3 with a DRE volume of ca. 290 km3, and an ejected mass of 1.1 × 1012 kg, which points out to a paroxysmal eruption (VEI 6-7).

Increasing the efficiency of the thermal power units at zoning of heat load curve

The article deals with the work of heat and power units of thermal power plants in the conditions of disaggregation of the heat load schedule. The purpose of the work is to increase the efficiency of operation of CHP units operating under the conditions of the zoned temperature schedule. To achieve the obtained results, mathematical modeling based on the methods of differential-exergetic and thermodynamic analysis; methods of material, energy and exergetic balances. Research has shown that in order to increase the efficiency the original method of splitting the temperature graph into three zones can be used, each of which is characterized by the method of regulation of heat supply, and to assess the effect of the minimum fuel consumption criterion can be used. The method of determining the equivalent design temperature, which takes into account the regime peculiarities of heat and power units in the form of a method of regulation of heat supply, is developed. Study has shown that three design points should be available when zoning the temperature schedule. Based on optimization calculations for standard sizes of heat and power units of a wide range of capacities, the calculations show that the optimal parameters of heat and power units in the conditions of zoning of the temperature schedule as a whole correspond to the standard values. In addition, it is shown that in each zone of the temperature schedule there is a saving of fuel, which can be from 3 to 30% depending on the type of power unit, its capacity and zone of the temperature schedule, and the annual fuel consumption of the heat and power units can be reduced by approximately 10%. It is shown that when conventional power units operate according to the zoned temperature schedule and in the first zone (quantitative regulation), preference should be given to power units with steam production. In the second zone (mixed regulation), the operation of power units with steam extraction and heat and power units is equivalent. In addition, in the third zone (qualitative regulation) preference should accrue to heat and power units.

Web-based System for Decision Support on Surface Irrigation Modernization

The purpose of this paper is to describe a web-based system to assist on-farm design and management of surface irrigation systems. This application was designed to be an appropriate tool for generating design alternatives associated with attributes of technical, economic, and environmental nature, and handling and evaluating a large number of input and output data. It also allows the evaluation and ranking of design alternatives using multicriteria analysis where criteria are weighted according to the priorities and perception of the designer and users, and provides an appropriate dialogue between the designer and the user, with an effective help support with information about equipments and irrigation practices. The application has tools for the resolution of specific problems, such as land leveling, pipe sizing and economic calculation. Built with a simple user friendly interface, with several optional languages and online help for technical aspects, this tool will contribute to support the dissemination of knowledge, design procedures and field practices of surface irrigation. Tests and demonstrations are being done on Hetao Irrigation District, China.

Effect of Zr on nanocrystalline Al-4.5 wt.% Cu alloy and its strengthening mechanisms prepared by mechanical alloying

Abstract Synthesis and characterization of Al, Al99.5Zr0.5, Al99Zr1 and Al97Zr3 nanostructures developed by high energy ball milling have been carried out in the present study. Mixtures of Aluminium and Zirconium were added to Tungstan carbide vial (Spex Sample Prep) in the desired quantities. The powder mixtures were milled in a Spex 8000 mixer/mill for 500 min to prepare the required nanocrystalline material. Milled powders were compacted in a cylindrical (8 mm dia) tool steel die under an uniaxial applied pressure 99.5 Mpa in a hydraulic pellet press. The compacted milled powders (pellet) were annealed under 2% H2 (bal. Ar) for 1 h at temperatures from 350 to 500 °C and holding at the same temperature for 1 h. The extents of alloying, structural and morphological changes of the nanocrystalline material in the powder form were analyzed and studied using X-ray diffractometer. X-ray diffraction data was analyzed by using X’Pert highscore plus for the calculation of crystallite size and lattice microstrain (%). The Vickers microhardness of all samples was also measured.

Introducing the “Derived Root-system Radius” – An attempt at an evidence-supported-calculation for calculation of buffer zone size in respect of Ancient Semi-natural Woodland, Ancient Trees & Veteran Trees

ABSTRACTGovernmental Standing Advice in England recommends a minimum 15 m buffer zone from Ancient Semi-natural Woodland (ASNW), or potentially longer distances for Ancient Trees (AT) and Veteran Trees (VT). This “one-size-fits-all” approach does not account for differences in the biology of individual tree species, or the environmental niches they occupy. The effective capillary range of trees further suggests that in some situations the Standing Advice potentially underestimates the zone of water influence. On the basis of published data linking root area to canopy spread, the estimated root areas of trees in a field sample (n = 112) were defined as the Derived Root-system Radius (DRSR). These results were significantly different from distances recommended within the Standing Advice, which might, therefore, be inadequate to safeguard the full extent of the roots in the greater proportion of the field study samples. In the case of AT and VT, the sensible approach will be to also anticipate any reduction in canopy area by applying both the diameter approach of the Standing Advice, and the DRSR, and adopting the greatest buffer zone.

Study of CoxPt1−x nanoalloy formation mechanism via single-source precursors

This paper is devoted to the study of formation mechanism of metal solid solutions during the thermolysis of single-source precursors in Co–Pt systems with a wide range of superstructural ordering. It is shown that the thermal decomposition of [Pt(NH3)4][Co(C2O4)2(H2O)2]·2H2O salt in helium is critically different from that under hydrogen atmospheres. Thermal degradation under the helium atmosphere is followed by a gradual reduction of platinum and cobalt, and at each thermolysis temperature only one phase is present. At 380 °C an equiatomic Co0.50Pt0.50 solid solution is formed (a = 3.749 (4) Å, Fm−3m space group, V/Z = 13.17 Å3, crystallite size: 5–7 nm). When the precursor is decomposed under a hydrogen atmosphere, the process proceeds mainly through the simultaneous reduction of the platinum and cobalt atoms, and at each temperature section two metal phases are present. The formation of the close to equiatomic Co0.50Pt0.50 solid solution (a = 3.782 (4) Å, Fm−3m space group, V/Z = 13.52 Å3, crystallite size: 7–9 nm) occurs at 450 °C. The calculations of crystallite sizes are confirmed by transmission electron microscopy data.