bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refined chloride mass‐balance method and its application in Saudi Arabia
Authors: Subyani Ali , Şen Zekai 
Published: October 2006

AbstractThe rainfall and infiltration elements of the hydrological cycle in arid regions are characterized by temporal and spatial variations that are random and sporadic. Consequently, the chloride concentration in rainfall has a similar behaviour. Despite this, the classical chloride mass balance (CMB) approach only employs arithmetic and weighted averages for recharge estimation. In this paper, the classical CMB method is modified by taking into account some perceived deficiencies in the methodology. The modified CMB method takes into consideration additional statistical parameters, namely variances and the correlation coefficient between variables concerned based on the application of the perturbation method. Strategic aquifer planning in the Kingdom of Saudi Arabia requires a quick method for estimating groundwater recharge in order to determine the temporal management of available water resources. To demonstrate the difference between the classical and the refined CMB methods, both were applied to a representative basin, i.e. Wadi Yalamlam, in the western part of Saudi Arabia. Based on the refined calculations, recharge to groundwater is found to be 11% of the effective annual rainfall. This refined method provides higher recharge rates because it takes into account the actual variability in the variables concerned and can, thus, improve the accuracy of future groundwater recharge estimation studies. Copyright © 2006 John Wiley & Sons, Ltd.
Groundwater recharge in the Akaki catchment, central Ethiopia: evidence from environmental isotopes (δ18O, δ2H and 3H) and chloride mass balance
Authors: Demlie Molla , Wohnlich Stefan , Gizaw Birhanu , Stichler Willibald 
Published: October 2006

AbstractRecharge patterns, possible flow paths and the relative age of groundwater in the Akaki catchment in central Ethiopia have been investigated using stable environmental isotopes δ18O and δ2H and radioactive tritium (3H) coupled with conservative chloride measurements. Stable isotopic signatures are encoded in the groundwater solely from summer rainfall. Thus, groundwater recharge occurs predominantly in the summer months from late June to early September during the major Ethiopian rainy season. Winter recharge is lost through high evaporation–evapotranspiration within the unsaturated zone after relatively long dry periods of high accumulated soil moisture deficits. Chloride mass balance coupled with the isotope results demonstrates the presence of both preferential and piston flow groundwater recharge mechanisms. The stable and radioactive isotope measurements further revealed that groundwater in the Akaki catchment is found to be compartmentalized into zones. Groundwater mixing following the flow paths and topography is complicated by the lithologic complexity. An uncommon, highly depleted stable isotope and zero‐3H groundwater, observed in a nearly east–west stretch through the central sector of the catchment, is coincident with the Filwoha Fault zone. Here, deep circulating meteoric water has lost its isotopic content through exchange reactions with CO2 originating at deeper sources or it has been recharged with precipitation from a different rainfall regime with a depleted isotopic content. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of land‐use changes on hydrological processes in the middle basin of the Heihe River, northwest China
Authors: Wang Genxu , Liu Jingqi , Kubota Jumpei , Chen Ling 
Published: October 2006

AbstractThe effects of land‐use changes on the runoff process in the midstream plain of this arid inland river basin are a key factor in the rational allocation of water resources to the middle and lower reaches. The question is whether and by how much increasingly heavy land use impacts the hydrological processes in such an arid inland river basin. The catchment of the Heihe River, one of the largest inland rivers in the arid region of northwest China, was chosen to investigate the hydrological responses to land‐use change. Flow duration curves were used to detect trends and variations in runoff between the upper and lower reaches. Relationships among precipitation, upstream runoff, and hydrological variables were identified to distinguish the effects of climatic changes and upstream runoff changes on middle and downstream runoff processes. The quantitative relation between midstream cultivated land use and various parameters of downstream runoff processes were analysed using the four periods of land‐use data since 1956. The Volterra numerical function relation of the hydrological non‐linear system response was utilized to develop a multifactor hydrological response simulation model based on the three factors of precipitation, upstream runoff, and cultivated land area. The results showed that, since 1967, the medium‐ and high‐coverage natural grassland area in the midstream region has decreased by 80·1%, and the downstream runoff has declined by 27·32% due to the continuous expansion of the cultivated land area. The contribution of cultivated land expansion to the impact on the annual total runoff is 14–31%, on the annual, spring and winter base flow it is 44–75%, and on spring and winter discharge it is 23–64%. Once the water conservation plan dominated by land‐use structural adjustments is implemented over the next 5 years, the mean annual discharge in the lower reach could increase by 8·98% and the spring discharge by 26·28%. This will significantly alleviate the imbalance between water supply and demand in both its quantity and temporal distribution in the middle and lower reaches. Copyright © 2006 John Wiley & Sons, Ltd.
A model of the wave and current boundary‐layer structure
Authors: Shi John Z. , Lu Li‐Feng 
Published: October 2006

AbstractA model of the wave and current boundary‐layer structure was developed using the k–ε turbulent closure model. The finite‐difference method was used to solve the governing equations. Vertical logarithmic grids and equal time steps were adopted. The following modelled simulations were obtained: (1) vertical profiles of wave velocity amplitude, eddy viscosity coefficient and turbulent kinetic energy with waves only; (2) vertical profiles of wave velocity amplitude, mean current velocity, eddy viscosity coefficient and turbulent kinetic energy with waves having a following current. To test the validity and the rationality of the present model, vertical profiles of modelled wave velocity amplitude and mean velocity were compared with corresponding experimental results available in the literature. Copyright © 2006 John Wiley & Sons, Ltd.
Selenium labeled fatty acids as potential myocardial imaging agents
Authors: Sadek Samy A. , Basmadjian Garo P. 
Published: October 2006

AbstractSix 75Se labeled fatty acid analogues were synthesized : 3‐selena‐[75Se]pentadecanoic acid, 4‐selena[75Se]hexadecanoic acid, 3‐selena[75Se]heptadecanoic acid, 4‐selena[75Se]octadecanoic acid, 3‐selena[75Se]nonadecanoic acid, and 4‐selena[75Se]‐eicosanoic acid. Selenious acid was reduced with NaBH4 in buffer pH 6.0. The nucleophile produced, NaSeH was reacted with different alkyl halide to form the corresponding selenol. To this was added an aqueous solution of the sodium salt of either iodoacetic acid or 3‐bromopropionic acid to form the sodium salt of the desired fatty acid. The free fatty acids were extracted in ether after acidification of the solution.
Photochemical enrichment of diacetyl [15‐3H] gibberellin‐A3‐7‐aldehydes by a tritium isotope effect
Authors: Lischewski M. , Liebisch H.‐W. , Adam G. 
Published: October 2006

AbstractDuring photocyclisation of 15α‐ and 15α‐tritiated diacetylgibberellin‐A3‐7‐aldehydes to the cyclobutanols we found an enrichment of the tritium labelled starting aldehydes by an isotope effect. The mechanism of the sterically controlled abstraction of the 15α‐hydrogen/tritium‐atom is discussed.
Synthesis of 14C‐labelled benzetimide‐HCl
Authors: Van Wijngaarden I. , Soudijn W. 
Published: October 2006

AbstractThe synthesis of 14C‐benzetimide (dl‐1‐benzyl‐4‐(2, 6‐dioxo‐3‐phenyl‐3‐piperidyl)‐piperidine hydrochloride), using benzyl cyanide 14C (from K14CN and benzyl bromide) as starting material, is described. The five steps synthesis results in an overall yield of 38% of labeled benzetimide HCI (calculated on KCN used) with a specific activity of 0.5 mC/mM.A seemingly preferent alternative route with the aid of 14C‐acrylonitrile could not be followed because of the instability of the labelled acrylonitrile (rapid polymerization).
The stability of benzetimide‐HCI at 37° C with varying pH is examined.
Compound Noise: Evaluation as a Robust Design Method
Authors: Singh Jagmeet , Frey Daniel D. , Soderborg Nathan , Jugulum Rajesh 
Published: October 2006

AbstractThis paper evaluates compound noise as a robust design method. Application of compound noise as a robust design method leads to a reduction in experimental effort. The compound noise strategy was applied to two types of situation: the first type has been described with active effects up to two‐factor interactions and the second type has been described with effects up to three‐factor interactions. These two situations are illustrated with help of case studies. The paper provides theoretical justification for the effectiveness of the compound noise strategy as formulated by Taguchi and Phadke. For example, we found that the compound noise strategy is very effective for systems which exhibit effect sparsity. This paper gives an alternative procedure to formulate a compound noise, distinctly different from Taguchi's formulation. The alternative method requires less information to formulate compound noise as compared to Taguchi's formulation. Overall, the paper studies the effectiveness of such an alternative formulation, outlines scenarios where compound noise as a robust design method can be effectively used and gives alternative strategies for the systems on which compound noise cannot be effective. Copyright © 2006 John Wiley & Sons, Ltd.
Nonlinear systems possessing linear symmetry
Authors: Cheng Daizhan , Yang Guowu , Xi Zairong 
Published: October 2006

AbstractThis paper tackles linear symmetries of control systems. Precisely, the symmetry of affine nonlinear systems under the action of a sub‐group of general linear groupGL(n,ℝ). First of all, the structure of state space (briefly, ss) symmetry group and its Lie algebra for a given system is investigated. Secondly, the structure of systems, which are ss‐symmetric under rotations, is revealed. Thirdly, a complete classification of ss‐symmetric planar systems is presented. It is shown that for planar systems there are only four classes of systems which are ss‐symmetric with respect to four linear groups. Fourthly, a set of algebraic equations are presented, whose solutions provide the Lie algebra of the largest connected ss‐symmetry group. Finally, some controllability properties of systems with ss‐symmetry group are studied. As an auxiliary tool for computation, the concept and some properties of semi‐tensor product of matrices are included. Copyright © 2006 John Wiley & Sons, Ltd.
The latent resources of the child's mind
Authors: Hess Robert D. 
Published: October 2006

AbstractDr. Hess was Asked to prepare this paper for presentation at several of the conferences in connection with the NASDTEC‐AAAS Study of Guidelines for Science and Mathematics in the Preparation Program of Elementary School Teachers in the winter and spring of 1961–62. His task was to stimulate thought by the conference participants on various issues related to the education of elementary school science and mathematics teachers. His thoughts may also stimulate science educators to consider research in the area of early experience in the learning of science.
A psychologist's counsel on curriculum design
Authors: Gagné Robert M. 
Published: October 2006

AbstractThis paper was read at the Conference on Science Instruction in Elementary and Junior High Schools sponsored by the AAAS Commission on Science Instruction at Cornell University in July, 1962. Dr. Gagné's assignment was to set forth some ideas on curriculum development which would stimulate thought and discussion by the conferees. It is hoped that his paper will do the same thing for JRST readers and that their reaction will appear in Comment and Criticism in subsequent issues.
What should we teach in biology?
Authors: Novak Joseph 
Published: October 2006

AbstractDr. Novak, who is Associate Professor of Biological Education at Purdue University, prepared this article originally for News and Views of NABT, an official publication of the National Association of Biology Teachers, and it was published there in April, 1963. In view of its importance to science educators, the article is reprinted here with the permission of Dr. Novak and NABT.
The curriculum in science for an African school
Authors: Watson Fletcher G. 
Published: October 2006

AbstractA number of American universities and other educational agencies are presently involved in the development of educational programs in the emerging nations of the world. Based‐on recent news reports from Washington, there will apparently be encouragement from the federal government for American educators and educational institutions to provide more of this kind of foreign aid. This article describes the science curriculum which Professor Fletcher Watson and his associates have prepared for the Comprehensive Secondary School in Western Nigeria. It was prepared as a working paper in November, 1962, in anticipation of the school's opening early in 1968. Professor Watson has agreed to provide additional reports for JRST readers on the evolution of the instructional program and the special problems encountered. These will be published in later issues of JRST.
A comparative study of selected needs, values, and motives of science and non‐science teachers
Authors: Bledsoe Joseph C. , Morris Kenneth T. 
Published: October 2006

AbstractA report by Eugene Lee which appeared in an earlier issue of JRST described differences between science teachers and scientists. This study serves to enlarge our understanding of the science teacher by describing differences in personality traits between science teachers and non‐science teachers presently in service.
Cognitive development and the learning of elementary concepts
Authors: Wohlwill Joachim F. 
Published: October 2006

AbstractWohlwill calls for longitudinal studies and a sequential analysis to help solve the mystery of cognitive development. He holds that as a child develops, his perceptual set in approaching problems is supplanted by a different set which has to do more with symbolic operations relating to concepts. The development of this new set is discussed together with the role of measurement in the developmental process. Implications are drawn for providing general types of early experiences to facilitate cognitive development.
The development of the concept of acceleration in elemewtary school children
Authors: Raven Ronald J. 
Published: October 2006

AbstractNinety‐six children from the third grade through the sixth grade were given speed tasks and acceleration tasks. The results of the study suggest that the speed and acceleration tasks that require intensive logical operations could be used by the third and fourth grade children. The data also indicate that the speed and acceleration tasks that use extensive logical operations could be used by some fifth and sixth grade children.
Changing attitudes toward science: Undergraduates in 1967 and 1971
Authors: Schwirian Patricia M. , Thomson Barbara 
Published: October 2006

AbstractThe purpose of the study was to examine the change in attitudes toward science and the scientific institution which had occurred among undergraduate university students between 1967 and 1971. Two similar cohorts of university undergraduates were given Form A of the Schwirian Science Support Scale (Tri‐S) in 1967 and 1971. The populations were 398 students and 153 students, respectively. Data concerning relevant contingent independent variables were also collected.The data were analyzed utilizing nine, two‐way analyses of variance. The major independent variable, time of administration, (1967 and 1971) was always one factor; the second factor in each ANOVA consisted of each of the nine contingent independent variables: (1) age; (2) sex; (3) religious preference; (4) father's education; (5) mother's education; (6) father's occupation; (7) academic major; (8) hometown size; and (9) type of high school.The data from the nine, two‐way ANOVA's show significant differences ( p < .05 ) in only two instances. In the case of the association of the Tri‐S Scores with father's occupation at times one and two, it was observed that the higher the status of the father's occupation, the higher the student's Tri‐S score. This relationship was observed in both 1967 and 1971; there was no significant effect of time. Statistically significant differences in Tri‐S scores were also observed among students from different sized hometowns; and in this case, there was a change over time. In 1967 students from small and medium‐sized communities had significantly lower Tri‐S scores than students from farms and large cities. By 1971 the mean scores of the students from small and medium sized communities had increased, producing scores slightly higher than the farm and city students.The findings indicate that the 1971 Midwestern university students in the sample are no less positive in their attitudes toward science than their 1967 counterparts. No significant differences between overall 1967 and 1971 scores exist and no significant differences over time were observed by age, sex, religious preference, father's or mother's education, father's occupation, academic major, or high school type.
The Israeli “Bagrut” examination in BSCS biology
Authors: Jungwirth E. , Dreyfus A. 
Published: October 2006

AbstractThis paper describes the rationale, construction, administration, and analysis of an externally set matriculation examination for BSCS students at the end of the 12th grade. The examination consisted of three equal parts: (1) functional information; (2) identification and application of principles; and (3) contributory mode understanding of the principles of biological enquiry.The predetermined difficulty level proved to be only slightly overambitious, so that individual means had to be only slightly adjusted in order to meet the national norms.Diagnosed deficiencies were concentrated mainly in the spheres of statistical treatment of experimental data, suggestions for technical arrangements of the experimental set‐up, and replications of the experiment.Hope was expressed, that the continued use of an examination of this type, would help to eliminate the discrepancy between objectives emphasized by school teachers and those stressed by the BSCS examination (illustrated by the very low correlation between teachers' grades and results on this examination).
Conservation concepts in elementary chemistry
Authors: Hall John Ruthven 
Published: October 2006

AbstractConservation of chemical identity, composition, and mass are essential to the basic understanding of chemistry. In an investigation carried out with 11 to 12 year old children, using techniques analogous to those of Piaget, it is shown that, even after the completion of an introductory course in chemistry over a nine month period, conservation had not been attained in a considerable proportion of subjects. The frequencies of non‐conservation responses were in the order composition > identity > mass. It is concluded that re‐examination of introductory courses with a view to facilitating attainment of conservation may be called for.
The effects of the use of activities of sapa on the oral communication skills of disadvantaged kindergarten children
Authors: Huff Phyllis , Languis Marlin 
Published: October 2006

AbstractThe study investigated the effects of participation in the activities of Science‐A Process Approach (SAPA) on the oral communication skills of disadvantaged kindergarten children. Experimental‐control group, pretest‐posttest research design was employed. The investigator designed the Test of Oral Communication Skills (TOCS) to measure students' oral communication skills. Two experimental groups (one morning and one afternoon, N = 52) and two control groups (one morning and one afternoon, N = 48) were randomly assigned from two kindergarten classrooms (morning and afternoon classes in each) in an inner‐city school in Columbus, Ohio. The investigator provided the science instruction to all students. Experimental subjects received 22 half‐hour lessons from exercises a through k of Part A, SAPA. Control subjects received 22 lessons from Springboards to Science, a teacher demonstration, class discussion type of kindergarten curricuoum used in the school system. The treatment period spanned 12 academic weeks.Analysis of variance of TOCS pretest scores showed no significant differences among any of the means of the four groups. Analysis of covariance of TOCS posttest scores revealed differences significant at .05 or beyond in the mean scores of the experimental groups and control groups for total oral and total receiving skills and for six of the eight subskills measured by TOCS. Application of the Tukey (b) test revealed that experimental group mean scores exceeded control group mean scores in every TOCS skill and subskill area and that in total oral transmitting subskills both experimental group mean scores were significantly greater at .05 level or beyond than corresponding mean scores for both control groups.Within the parameters of this study, it may be concluded that when the activities and teaching strategies of SAPA curriculum are presented to disadvantaged kindergarten children, their oral communication skills, especially the transmitting (speaking) skills, are clearly enhanced.
An analysis of the assumptions underlying the taxonomy of educational objectives: Cognitive domain
Authors: Stedman Carlton H. 
Published: October 2006

AbstractThe assumption that the first four cognitive levels of the taxonomy of educational objectives are arranged hierarchically and that this hierarchy is cummulative was evaluated. Mental ability and motivation scores were used to divide 144 high school biology students into six blocks. A 93‐frame program in genetics was administered, and at the completion of the program the subjects took a 28‐item posttest that had subscores for the cognitive levels of knowledge, comprehension, application, and analysis. Results indicated that no significant differences were found between knowledge and comprehension or application and analysis. A significant difference was found beyond the .0005 level, however, between comprehension and application. These results indicate that the cognitive processes at work at each level of the taxonomy may not be equitable, and that the previously mentioned assumptions are at least questionable.
The effects of a structured learning sequence on Children's correlative thinking about biological phenomena
Authors: Nous Albert , Raven Ronald 
Published: October 2006

AbstractThe purpose of this study was to determine if the achievement on correlational thinking tasks could be enhanced by a set of structured training exercises. The exercises were based on Piaget's analysis of the development of correlative thinking in adolescents. The achievement of the ninth grade students was greater than the achievement of the fifth and seventh grade students. However, some of the ninth grade students exhibited difficulty with the equivalence and reciprocal exclusion operations that were necessary for the solution of the correlation tasks. The results of the study suggest that the ninth grade students may be in the transition zone for this particular operation.