294 research outputs found
Data-Based Mechanistic approach to modelling of daily rainfall-flow relationship : a case of the Upper Vaal water management area
Published ArticleAlthough deterministic models still dominate hydrological modelling, there is a notable paradigm shift in catchment response modelling. An approach to represent the daily rainfall-flow (R-F) relationship using Data-Based Mechanistic (DBM) modelling is presented. DBM modelling is an inductive empirical transfer function (TF) approach relating input to output. The study used secondary data from the Department of Water Affairs and Forestry for the Upper Vaal water management area at station C1H007. The R-F model identification and optimisation was implemented in the CAPTAIN Toolbox in MATLAB. The best estimated R-F model was a 2nd order TF with an input lag of one day and R 2T= 56%. In mechanistic interpretation, three parallel flow pathways were discerned; the fast flow, slow flow and the loss component each constituting 49.8%, 24% and 26.2% of the modelled flow respectively. The study demonstrates that the approach adopted herein produces reasonably satisfactory results with a minimum of the readily available catchment data
Comparative Haemolymph Biochemical Properties of Giant African Land Snail (Archachatina marginata) from Nigeria
The Giant African Land Snails (GALS) is a very important micro livestock that is consumed widely within several regions in sub-Saharan Africa which differ in their vegetation types and climatic factors. Studies have shown that diet and stocking density influence properties of the snail haemolymph. This study examines the haemolymph biochemical properties of the land snail, (Archachatina marginata) from south-west (Ekiti, Lagos, Ogun, Ondo, Osun and Oyo). Organic (protein, lipids, glucose) and inorganic (Na, K, Ca, Cl, PO4) composition of snails’ haemolymph were determined by standard methods. Results showed that GALS from Oyo state had the highest lipids and glucose concentrations in the haemolymph while Ondo and Ekiti states recorded the least. Protein was the most abundant (33.83g/l-49.37g) organic substance while lipids were the least (23.93mg/dl-33-93mg/dl). There were significant differences (P<0.05) in the concentrations of inorganic substances in the haemolymph across the six states. Snails from Oyo state recorded significant higher (p<0.05) concentrations of Na+, Ca2+ and Cl- than those of other states. Also, Na+ and Cl- were the most common anions in snails’ haemolymph from the six states. This current study concluded that snails from Oyo state had better haemolymph biochemical properties than other south west states of Nigeria. DOI: 10.7176/JBAH/10-12-02 Publication date:June 30th 202
Assessment of utilization of postpartum care services among women in Webuye West, Bungoma County, Kenya
Background: Postpartum care (PPC) is an important link in the continuum of care for maternal health. PPC services are essential, aim being to prevent any complications, poor outcomes like morbidity and mortality to ensure a healthy mother. The postpartum period is critical because most maternal deaths occur during this time, yet this is the most neglected period for quality care provision.Objective: To assess utilization and factors influencing utilization of PPC services among women in Webuye West, Bungoma County, Kenya.Design: A descriptive cross sectional study.Setting: Webuye West, Bungoma County, Kenya.Subjects: All women of reproductive age with living children aged 6-9 months.Results: The study revealed that 33.6% utilized PPC services; poor attendance of mandatory visits at less than 40 %, and all visits being positively correlated (r p 0.000) to utilization. On socio cultural factors 85.8% reported staying indoors for specified period influenced use of PPC services and 57.3% stated that traditions demand them to do so. Cultural beliefs and practices are performed and seclusion of up to one month of this 55.7% attested to. Religious beliefs and practices was dependent on use of PPC by 59.4% (X2 p=0.011).On knowledge majority 70.6% knew the services during ANC and from HCWs, but less than 15.4% and 28.2 % knew the mandatory and targeted visits respectively. The 1st and 4th visits being dependent on utilization (X2, p<0.001). On health facility factors the mean distance to facilities is 1.78 km. Even though the majority of available service was basic, majority, 74.8% reported availability with 40.9% having received the services during all their visits. Majority 75.9% of HCWs were friendly and helpful. Half of the women paid for services and average waiting time was 31-60 minutes.Conclusion: PPC service utilization is low marked by poor attendance of visits. Utilization of PPC is dependent on; religious beliefs and practices (X2=0.011), Knowledge on sources of information from MCH booklets and ANC visits (X2 p<0.001); knowledge on who to attend after birth (X2, p<0.001) and timings of PPC visits. Health facility related factors are availability of HCW, their helpfulness and friendliness and waiting time (X2p<0.001). Distance to the health facility and charges for services (X2 p=0.005)
The Asian entrepreneurship core in COVID-19 period: value chains, specialized education, massive participation of women and strategic accompaniment
The document seeks to follow up on companies, entrepreneurs and States, on the issue of strategy and entrepreneurship. For this, two parts are taken, “Companies and take-off strategies typical of central and southeast Asia, before the pandemic”, there are unicorn companies, ventures, new versions of organizations before COVID, period from 2012 to 2019. The cases to be studied come from companies, States, organizations, which are located in the center, such as in Southeast Asia: the Republic of India and the People’s Republic of China. It also takes the leading countries of Southeast Asia, led by Japan, first-generation of the Asian Tigers, Singapore, South Korea, Republic of China Taiwan (ROC); second generation, Thailand, Indonesia, Vietnam, among others. Then, strategic cases are described, analyzed, and sought, in the period 2021-2022, the same countries of Central Asia, plus Japan, the first-generation Tigers, all those previously analyzed, plus Hong Kong and the Second generation, all the analyzed in the previous period, plus Malaysia and Cambodia (OJEDA F. A., 2014). Sectors associated public policies, business strategies, exact cases of companies are observed, for each country, before and after the pandemic until today, 2022. With this research scheme, the reader establishes a “road map” of the companies, which has been generated from a highly volatile international environment, but with great opportunities. It is also an attempt to show a business “catalogue of practices” from these countries, which can be an example for Western organizations, in times of global crisis and international price volatility, especially affecting the value chains of food commodities, energy and basic electronic supplies
Airflow profile study of a compost dairy barn using a low-cost 3D-printed anemometer network
Mechanical ventilation is commonly used for environmental thermal regulation inside
closed-field agricultural production systems. Analyzing the air distribution inside these facilities
and the correct operation of the fans can be a challenging. This could be determined using cost
prohibitive techniques as particle image velocimetry or deploying large wind sensors networks
on-site. To avoid this limitation without a lack of measurement accuracy, this research was
focused on developing and test a low-cost anemometer network based in low cost propeller’s
anemometers, built using fused 3D-printed and open-hardware platforms. Four propeller
anemometers with three to six blades were simulated using the 6-DOF method of ANSYS
computer fluid dynamics software. Similar results were obtained for all the simulated models
with minor differences. Anemometers were tested in an open circuit wind tunnel before to be
evaluated in two open compost dairy barn building using high-volume low-speed and low-volume
high-speed fans. Data were analyzed by employing contour maps, descriptive statistics and
correlation. The results show that the anemometer network determines the fan’s wind profile for
wind speeds over 0.7 m s-1
and it was possible to determine the facilities spots with ventilation
problems. The proposed anemometer network and methodology are a good alternative to analyze
the operating conditions of the tested agricultural facilities and optimize its performance
A variable step size perturb and observe algorithm for photovoltaic maximum power point tracking
High-energy impact testing of agglomerated cork at extremely low and high temperatures
Agglomerated cork, made from the scraps of wine stoppers, has been finding a wide set of applications due to its excellent thermal and acoustic insulation properties. The random orientation of grains makes the material nearly isotropic, while its dominant viscoelastic behaviour and nearly zero Poisson's ratio make the material also very interesting in applications where dimensional stability is highly demanded. With proven properties, agglomerated cork has been widely used for manufacturing of architectural facades, in civil construction, aerospace engineering and even home appliances production. For outdoor applications, the performance of cork material under different working temperatures is a vital point to be considered. This paper assesses the capability of five different types of cork agglomerates to withstand 500 J impact energy under different temperature conditions. Keeping 11.2 kg impact mass and velocity of 9.2 m/s, impact tests were performed for a wide range of temperatures starting from sub-zero temperature (−30°C) up to 100°C in order to cover a full span of working circumstances. Results show significant variations of amount of absorbed energy depending on testing temperature, calling the attention of designers and product developers for important aspects to be considered upon the application of this material under extreme weather conditions.publishe
Comparison of airflow homogeneity in Compost Dairy Barns with different ventilation systems using the CFD model
In the pursuit of high milk productivity, producers are using confinement systems in
order to improve performance and animal welfare. Among the housing systems, the Compost
bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows
move freely. Generally this area is covered with carbon source material (such as sawdust or fine
dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures
the aerobic composting process. The ventilation in these facilities has the function of
dehumidifying the air, improving the air quality, drying the bedding, improving the thermal
comfort conditions of the confined animals. This work aimed at validating a computational model
using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows
generated by different forced ventilation systems used in CBP barns. Two CBP barns were
compared with different ventilation systems: high volume low speed (HVLS) and low volume
high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict
the flows generated by both types of fans. It was concluded that the use of HVLS fans produced
a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation
in tropical conditions is necessary for the proper functioning of the system. In this study, the
systems used promoted the increase in air speed to levels close to adequate
Activation Energy And Enthalpy Of Decomposition For The Fe17sm2 Nitride
Decomposition studies of die Fe17Sm2N3 compound were done using a Calvet-type microcalorimeter and a simultaneous gravimetric and differential thermal analyzer (DTA). The results show that the decomposition has onset temperature of 570 °C and proceeds up to 900 °C, and presents only one well determined exothermic thermal event. The calorimetric measurement shows that the enthalpy associated with the decomposition is 69 kJ/mol. The activation energy of the process was also determined using the Kissinger method applied to the DTA signal. It was observed that there was only one activation energy for the decomposition process, with a value of 339 kJ/mol. © 1997 American Institute of Physics.818 PART 2B51095111Coey, J.M.D., Lawler, J.F., Sun, H., Allan, J.E.M., (1991) J. Appl. Phys., 69, p. 5Christodoulou, C.N., Komada, N., (1995) J. Alloys Compd., 222, p. 92Chen, S.K., Jin, S., Kammlott, G.W., Tiefel, T.H., Johnson Jr., D.W., Gyorgy, E.M., (1992) J. Magn, Magn. Mater., 110, p. 65Kim, K.-J., Sumiyama, K., Onodera, H., Suzuki, K., (1994) J. Alloys Compd., 203, p. 169F. A. O. Cabral, S. Gama, E. de morais, N. L. Sanjurjo, C. A. Ribeiro, and C. C. Colucci (to be published)Liu, J.P., Winkelman, A.J.M., Menovsky, A.A., Bakker, H., De Boer, F.R., Buschow, K.H.J., (1995) J. Alloys Compd., 218, pp. L15Kissinger, H.E., (1957) Anal. Chem., 29, p. 11Uchida, H.H., Uchida, H., Yanagisawa, T., Kise, S., Koeninger, V., Matsumura, Y., Koike, U., Kanneko, H., (1992) Proceedings of the 7th International Symposium on Magnetic Anisotropy and Coercicity in RE-TM Alloys, p. 342. , Camberra, (unpublished)H. Uchida, U. Koike, K. Kamada, V. Koeninger, Y. Matsumura, H. H. Uchida, T. Kurino, and H. Kanneko, in Ref. 8, p. 331Uchida, H.H., Uchida, H., Yangisawa, T., Kise, S., Susuki, T., Matsumura, Y., Koike, U., Kanneko, H., (1993) J. Alloys Compd., 196, p. 71Freeman, E.S., Carroll, B., (1958) J. Phys. Chem., 62, p. 39
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