Miracle-dz/UniFAR-FTUs huggingface dataset:
Constructal Design of Forced Convection Cooled Microchannel Heat Sinks and Heat Exchangers

Heat transfer from arrays of circular and non-circular ducts subject to finite volume and constant pressure drop constraints is examined. It is shown that the optimal duct dimension is independent of the array structure and hence represents an optimal construction element. Solutions are presented for the optimal duct dimensions and maximum heat transfer per unit volume for the parallel plate channel, rectangular channel, elliptic duct, circular duct, polygonal ducts, and triangular ducts. Approximate analytical results show that the optimal shape is the isosceles right triangle and square duct due to their ability to provide the most efficient packing in a fixed volume. Whereas a more exact analysis reveals that the parallel plate channel array is in fact the superior system. An approximate relationship is developed which is very nearly a universal solution for any duct shape in terms of the Bejan number and duct aspect ratio. Finally, validation of the relationships is provided using exact results from the open literature.Copyright © 2005 by ASME
Substitution Relationship Between The Agency Problem Control Mechanisms in Malaysia: Simultaneous Equation Analysis

This study investigates the substitution relationship (substitutability) between debt policy, insider ownership, and dividend policy as the agency problem control mechanism in Malaysia. If the substitution relationship exists between the agency control mechanisms, the agency problem can be reduced through this relationship. Reducing the agency problem as a result can increase the firm value proxied by Tobin’s Q. This study employs 396 firms sample listed on Malaysian Bourse from 2001 to 2004. To achieves the objectives, this study uses two-stage least square method. The results of this study indicate that the substitutability between debt policy, insider ownership, and dividend policy as agency problem control mechanism does not fully exist in Malaysia. Apparently the substitutability only exists for debt policy and dividend. There is no substitution between debt policy and insider ownership as well as between dividend policy and insider ownership. Key words: debt policy, insider ownership, dividend policy, agency problem, firm value
Comparison between the needle and roller electrospinning of polyvinylbutyral

The effect of the concentration of polyvinylbutyral solution on the process throughput and fibre properties was studied in needle and roller electrospinning. Whereas the polymer throughput is an optional independent parameter in needle electrospinning, it is a dependent parameter that is affected by both the material and process parameters in roller electrospinning. Polymer throughput increases considerably with an increasing concentration of polymer solutions in roller electrospinning. The properties of the nanofibers and the quality of the nanofiber layers were also studied. Fibre diameters increase with an increasing concentration in both techniques. Fibre diameters produced by needle electrospinning are smaller than those produced by roller electrospinning. The distribution of fibre diameters is rather narrow and not significantly dependent on the concentration of solutions in either technique.
Ultrasonic evaluation of temper-embrittlement for martensitic stainless steel

This research studied the possibility of non-destructive detection of temper-embrittlement in tempered CA-15 martensitic stainless steel (MSS). It was found that secondary hardening phenomenon existed in tempering temperature range of 573-673 K for the MSS in this study. Ultrasonic responses, both in terms of acoustic velocity and attenuation, exhibited changes with respective to the microstructure variation. Microstructural constituent of chromium carbide (Cr 23 C 6 type) precipitates was found to have resulted in the temper-embrittlement of the MSS and also was responsible for the changes of the ultrasonic behavior of the material.
Influence of strong magnetic fields on laser pulse propagation in underdense plasma

We examine the interaction between intense laser pulses and strongly magnetised plasmas in the weakly relativistic regime. An expression for the electron Lorentz factor coupling both relativistic and cyclotron motion nonlinearities is derived for static magnetic fields along the laser propagation axis. This is applied to predict modifications to the refractive index, critical density, group velocity dispersion and power threshold for relativistic self-focusing. It is found that electron quiver response is enhanced under right circularly-polarised light, decreasing the power threshold for various instabilities, while a dampening effect occurs under left circularly-polarised light, increasing the power thresholds. Derived theoretical predictions are tested by one- and three-dimensional particle-in-cell simulations.
Optimized re-entry input shapers

The paper deals with the design of optimized input shapers for non-vibrational control of flexible mechatronic systems. The described method is based on a combination of advantages from two approaches – precomputed control curves and on-line shapers. The strategy has two steps. Primarily, an optimized precomputed curve is found as a solution to the point-to-point control problem with respect to any requested optimization goals. Then it is transformed into an on-line shaper with the re-entry property. The resulting shaper transforms any arbitrary input signal to a non-vibrational one. In contrast to other techniques, the shaper length is not determined from the system natural frequency. The shaper can be easily modified with respect to position, velocity, acceleration or jerk control. The theoretical results are verified by experiments using a laboratory crane.
City liveability and housing in Nigeria: a case study oflow-income housing in Niger State

Studies on the liveability of cities have been on the increase due to their perceived aftermath significant contributions to the quality of life. Although the quality of life (QOL) has been studied from different disciplines, however, it does not mean absence of diseases or sickness rather QOL depends primarily on the living environment. The aim of this study is to examine the quality of life against the backdrop of the existing environment in the public low-income housing estates in Niger State of Nigeria. The conceptual framework for this study was developed based on empirical review. Based on the desktop literature the study used both subjective and objective measurements to investigate the liveability of the selected housing estates. Issues examined include the home environment, neighbourhood amenities,economic vitality, social environment and civic protection. Questionnaires were distributed to household heads in the selected three housing estates. The stratified random sampling technique used was to choose all types of homes. The data analysis techniques include; descriptive statistics, factor analysis and structural equation modelling (SEM). This study contributes to the existing body of knowledge in liveability studies in terms of model construct. It also uncovers the quality of life in public low-income housing in Niger State.
Determination of uranium internal dose exposure through soil digestion using RDRC and URODC software

This study was conducted to determine the dose of internal exposure through ingestion of soil in the vicinity of the repository facility in Bukit Kledang, Ipoh, Perak. Data from this study can assess the risk of radiation exposure to the health of local population, specifically blood, liver and bone cancers. Activities of radionuclide 238U in MG and M10 in the gastric phase are 1.118 ± 0.062 and 1.232 ± 0.073 Bq/kg, while the respective activities in the gastrointestinal phase are 0.553 ± 0.051 and 0.905 ± 0.082 Bq/kg. Samples of M10 recorded the highest reading of internal exposure in both phases. Digestion of 2 g soil from M10 samples on gastric phase generated the annual effective dose of 3.168 μSv/year with an assessment of cancer risk by 0.001% within 70 years to public. Organ dose for blood, liver and bone were 0.59, 11.60 and 65.95 μSv, respectively. Analysis of organ doses based on the concentration of 238U found that M10 has higher dose compared to MG. Risk assessment predicted for 70 years after the ingestion of the soil for blood cancer was 0.003% and liver cancer was 0.004% while the highest cancer risk was for bone cancer with 0.023%. Although the concentration of specific activity of 238U identified is low, it is shown that the internal dose exposure as a result of digestion of radionuclides are below the standard and can be considered as safe for public.
Self-regulated math instructions for pupils with learning disabilities

Abstract In this research, we considered the different impact two methods of teaching had on pupils’ ability to solve complex math problems. The methods considered were: self-regulated study and traditional teaching. We also examined the pedagogical consequences the differences made among the population of pupils with learning disabilities in special education classes within the standard elementary school system. In addition, we examined gender difference and its influence on the ability to solve complex math problems. The research assumption was that self-regulated learning will promote pupils’ achievements more than the traditional approach because it presents pupils with word problems, research tasks, concept presentation using illustrations and mathematical representations; comprehension of math properties, terms and the conceptual connections between them. The self-regulated approach to learning consists of a process that puts an emphasis on pupils’ active engagement with the study material wherein the traditional method of teaching, the emphasis is on the teacher and her frontal teaching time leaving pupils passive. There were forty (40) participants in the study, ranging in age from 9 to 10; all with learning disabilities and attending four different classes (grades 3 to 4). Two of these classes studied math using the self-regulated method, and the other two, the traditional method. The ability to solve challenging math problems was examined using a test that included four challenge questions from a collection of math skills evaluation tests. In addition, teachers were required to fill out a questionnaire that characterized the teaching method they used. The findings revealed that the ability to solve challenge problems in math among pupils that were taught using the self-regulated method was significantly higher than the ability of the pupils that were taught using the traditional method. No significant difference in the ability to solve challenge problems in math was observed based on gender influence. In addition, the differences in this ability did not vary based on gender influence while using either method of teaching. The research concluded with a recommendation to use the self-regulated learning approach in teaching math because it may contribute to the improvement of math strategic thinking and thus impact a variety of phenomena related to this pedagogical field such as reducing school dropout rates, promoting pupils’ achievements, and improving social interaction.
Modeling future glacier mass balance and volume changes using ERA‐40 reanalysis and climate models: A sensitivity study at Storglaciären, Sweden

(1) Modeling the response of glaciers to future climate change is important for predicting changes in global sea level rise and local water resources. We compute until the year 2100 the mass balance and volume evolution of Storglaciaren, a small valley glacier in Sweden, using a temperature index mass balance model. We focus on the sensitivity of results to the choice of climate model and variants of adjusting ERA-40 temperatures to local conditions. ERA-40 temperature and precipitation series from 1961 to 2001 are validated and used both as input to the mass balance model and for statistical downscaling of one regional and six global climate models (GCMs). Future volume projections are computed using area-volume scaling and constant glacier area. ERA-40 data correlate well with observations and capture observed interannual variability of temperature and precipitation. The mass balance model driven by several variants of ERA-40 input performs similarly well regardless of temporal resolution of the input series (daily or monthly). The model explains � 70% of variance of measured mass balance when the input temperatures are reduced by the lapse rate that maximizes model performance. Fitting ERA-40 temperatures to observations close to the glacier does not improve the performance of the model, leading us to conclude that ERA-40 can be used for mass balance modeling independent of meteorological observations. Projected future volume series show a loss of 50-90% of the initial volume by 2100. The differences in volume projections vary by 40% of the initial volume for six different GCMs input to mass balance model, while each volume projection varies by 20% depending on whether volume-area scaling or constant area is used and by 10% depending on details in the mass balance model used. The correction of biases in the seasonal temperature cycle of the GCMs with respect to the ERA-40 data is crucial for deriving realistic volume evolution. Static mass balance sensitivities to temperature and precipitation change in the 21st century are � 0.48 m yr � 1 K � 1 and 0.025 m yr � 1 per % increase, respectively.
Cannibalism in Dungeness crab Cancer magister: effects of predator-prey size ratio, density, and habitat type

Cannibalism between age classes has been reported for Dungeness crab Cancer magister Dana, and hypothesized to cause the cyclic behavior of the fishery. Recently, cannibalism among young-of-the-year (YOY) Dungeness crabs has been documented, and proposed as an alternative hypothesis to explain recruitment failure of later cohorts of megalopae in intertidal shell habitats already occupied by older YOY crabs. Furthermore, cannibalism among juveniles has also recently been reported for other crab species. This study experimentally addressed whether: (1) cannibalism rate by age classes 0+, 1+ and 2+ of Dungeness crabs Cancer magister of both sexes on YOY conspecifics is affected by habitat type; (2) cannibalism rate among YOY is affected by conspecific density and prey-predator asymmetry; and (3) YOY mutual interference and prey-predator asymmetry affect consumption rate. Predation rate by older crabs (age classes 1 and 2) on YOY was highest in mud habitat, intermediate in low shell density, and lowest in the high shell density treatment. These results show that shell habitat enhances production of YOY crâbs by increasing survival. Despite the fact that shell habitat decreased cannibalism rate of larger conspecifics on YOY, it did not affect cannibalism rate among juveniles. YOY crabs did not consume carapaces of conspecifics, while larger crabs consumed entire prey; this difference in amount of hard parts consumed suggests that although cannibalism may be common among YOY, it may not be detected by stomach analysis. Consumption of megalopae was affected by prey density, and also by the asymmetry between the prey and the predator. As predator density increased, the total consumption of megalopae increased, but proportional mortality per predator decreased. When other instar stages were used as prey, prey-predator asymmetry and prey density were not as important factors as predator density on cannibalism rate. Megalopae were the most vulnerable prey, and under certain circumstances YOY conspecifics may be able to decimate cohorts of settling megalopae. However, megalopae may find refuge from cannibalism when predator-prey size ratio is low, predator density is high, and probably when relative abundance of alternative prey is high (laboratory experiments were conducted using only conspecifics as prey). Cannibalism, or other 'processes that may have evolved in response to cannibalism, may be important factors regulating crab recruitment in natural populations and limiting crab production in artificial habitats.
Insect communities inhabiting Inonotus radiatus growing on Alnus glutinosa trees at northern and southern shores of boreal lakes

This is a study of the insect community associated to the wood-decaying fungus Inonotus radiatus found on Alnus glutinosa trees growing in riparian forests at the northern and southern shores of boreal lakes in the province Uppland. Little is known about this particular bracket fungus and its inhabitants. Insects were reared out at the laboratory from samples of fruiting bodies of the fungus taken at five lakes. During the fieldwork in 2009, data about several environmental variables was also taken. After the rearing period, these variables and their effects over the insects were analyzed. Special attention is paid to the comparison between the insect communities living at northern and southern shores of the lakes. We consider the microclimates at the northern and southern shores are different due to the dissimilar sun exposure they receive. The collected insect communities associated to opposite shores are not identical, but the variable shore exposition turned out to be influencing just four of the studied taxa. The variables which turned out to have a greater impact over the insect communities were lake, weight of the fungus and sun exposure. The preferences regarding successional stage of the fruiting bodies by some of the collected taxa are also presented. Most of them seem to be more attracted by older fruiting bodies than by the new and fresher ones. One red-listed beetle species has been recorded during the project, as well as three other species which were included in previous Red Lists although they are no longer on the Swedish Red List. Distributions of insect species are also revised to analyze the accuracy of the Red List.
Effect of GDP, Population and Interest Rate on Residential House Prices in Nairobi County, Kenya

Previous studies have shown an increasing trend in house prices over the past ten years and it is anticipated that the trend is likely to continue into the foreseeable future. This trend has been attributed to various factors, both microeconomic and macroeconomic. However, there is scant information on the effect of various macroeconomic factors such as GDP, population and interest rate on house prices in Kenya. Consequently, there is need for more research to be undertaken in order to determine the effect of such factors on house prices over time using the latest data. This study therefore sought to address the current literature gap by determining the effect of various macroeconomic factors on house prices in Kenya. In particular, the study sought to examine the effect of; GDP, population and interest rate on residential house prices in Nairobi count. To achieve this, the study adopted an explanatory research design as it attempted to explain the effect of GDP, population and interest rate on residential house prices for the period 2004-2016. The target population comprised of quarterly (2004Q1-2016Q4) observations of the House Price Index (HPI) and the quarterly observations of the variables. Data on quarterly observations of the House Price Index was obtained from Hass Property Consult Ltd while that on quarterly observations of the variables was obtained from Kenya National Bureau of Statistics and Central Bank of Kenya. Vector Error Correction Model (VECM) estimates were used to establish the long-run relationship between the determinants and residential house prices. Results confirm the existence of a long-run equilibrium relationship among variables in the model. The size of the coefficient of the error correction term (β = - 0.0004, p = 0.0383) suggests a relatively lower speed of adjustment from the short-run deviation to the long-run equilibrium. VECM coefficients specifically revealed that in the long-run GDP (β= - 0.6067, p = 0.0071) and interest rate (β = - 17.99, p= 0.0009) have a negative significant effect on house prices. Though having a negative relationship with house prices, the study failed to identify any long-run relationship between population and house prices (β= -0.5340, p = 0.4562). The study recommends that the government of Kenya should create an enabling environment for availability of credit to spur economic growth and hence check the house prices. Further, there is need to check on urban population growth so as to match the number of houses available with the increase in population. Keywords : House price Index, Gross Domestic Product, Interest Rate, Population.
Assessment of Impact of Early Stroke Rehabilitation on Hip Joint Mobility of the Affected Leg in Patients after Cerebrovascular Accidents

One of the main priorities of stroke rehabilitation is regaining patients’ independence in basic everyday activities. This paper is aimed at assessing impact of early stroke rehabilitation on hip joint mobility of the affected leg in patients after cerebrovascular accidents. The study included 30 subjects (13 men and 17 women) aged on average ±66.1, with hemiparesis, who were treated at the stroke unit and participated in a 4-week rehabilitation program. Measurements of passive and active motion ranges were conducted with a goniometer in both limbs: healthy and affected ones by stroke. There were statistically significant differences in motion ranges between healthy and affected limbs. Examination I revealed that affected limbs amounted to only 40% of physiological range, while in Examination II, the result reached 73%. The most significant motion limitations were noted in terms of bending, adduction and internal rotation, while the least significant in terms of external rotation and abduction. Exercises used during early stroke rehabilitation of hemiparesis patients considerably increased active motion ranges and maintained passive motion ranges in the hip joint of the affected limb. Patients with right-sided hemiparesis experienced much better improvement in hip joint motion of the affected limb. The 4-week period was insufficient to mobilize patients and help them regain full active mobility in the hip joint of the affected limb. These patients required further physiotherapy, until they fully regained functionality.
Variación de la distribución de carbono entre la raíz y la parte aérea en tres especies de pino Variation of carbon distribution between the root and the aerial part in three pine species

The amount of carbon allocated to the shoot and root varies between species. The carbon balance of the shoot and the root is critical for survival in the field. Therefore, the objective of this study was to evaluate carbon allocation through variables of growth and root morphology in Pinus michoacan, P. pesudostrobus and P. martinezzi plants, which have variation in survival in the field. The plants were growth in nursery and watered twice a week with tap water. At 150 days, the shoot and root biomass, specific root length (SRL) and root volume (RV), and the number, diameter (RD) and length (RL) of lateral roots were evaluated. The shoot and root biomass, RV and the LER were similar between P. pseudostrobus and P. martinezii, while P. michoacana had significantly higher values of these parameters in relation to the other two species. The number, RL and RD were higher in P. michoacana as compared to P. pseudostrobus and P. martinezii and these variables were higher in P. pseudostrobus regarding to P. martinezii. The carbon allocation varied interspecies and it was higher in the variables of root morphology. Therefore, it is recommended that root morphology parameters could be taken into account as indicators of quality plant.