Determination of Hydraulic Characteristics of Porous Pipe Irrigation Laterals and Water Distribution Pattern in Sandy Soil

Irrigation systems are well known for their low efficiencies. Microirrigation system is becoming popular even in humid areas because of the many advantages it offers. Microirrigation is really the first irrigation method that can potentially maximize productivity while conserving soil, water and fertilizer resources and simultaneously protecting the environment. Since a micro irrigation system can achieve very high application efficiency, it should be further explored even for supplemental irrigation in a high-rainfall tropical country like Malaysia, with annual rainfall exceeding 2500mm. Porous pipe is useful both for surface and subsurface micro irrigation systems and it can be used in a variety of ways to meet any irrigation need. However very little information is available about the discharge uniformity, operating characteristics and the moisture distribution pattern of porous pipe irrigation laterals. This research work on the hydraulics of two types of porous pipe was carried out to determine such performance criteria as the pressure-discharge relationship, pressure headloss, friction factor Reynolds number relationship and water dispersion in the soil. The water distribution pattern was observed in a soil box. Several lengths of imported porous pipes were subjected to various upstream pressure inputs to determine the average discharge along the lateral and the associated pressure losses

Virulence of entomopathogenic fungus, metarhizium anisopliae to sweetpotato whitefly, bemisia tabaci (hemiptera: aleyrodidae) under osmotic stress

The aim of the present study was to investigate the virulence of the entomopathogenic fungus Metarhizium anisopliae (isolates PR1 and GT3) under osmotic stress condition. The virulence study of the fungus was conducted by three ways—growth (germination, vegetative growth and sporulation); enzymatic activities (chitinase, protease and lipase) of M. anisopliae and percentage mortality of Bemisia tabaci to M. anisopliae. Conidia of M. anisopliae were produced under different osmotic stress conditions as SDA medium as control, SDA medium with 0.5 M NaCl, SDA medium with 0.5 M KCl, SDA medium with 1 M NaCl and SDA medium with 1 M KCl. The germination percentage, vegetative growth, sporulation, chitinase and protease activities were highest for control of PR1 isolate, reaching up to 97 %, 4.1 cm and 6.6 × 106 conidia/ml, 2.6 mU/ml and 1.7 µg/ml/min, respectively. These values decreased up to 86.7 %, 3.6 cm and 4.1 × 106 conidia/ml, 1.6 mU/ml and 1.0 µg/ml/min, respectively under osmotic stress. The lipase activity was highest for 0.5 M NaCl of PR1 isolate, reaching up to 18.2 µmol/ml/min. The mortality percentage of B. tabaci was highest for control of PR1 and GT3 isolates, reaching up to 83.9 and 83.8 %, respectively. These values decreased up to 77.4 and 77.5 %, respectively under osmotic stress. This paper concludes that both the isolate PR1 and GT3 are virulent to B. tabaci under osmotic stress condition

Understanding patient and family experiences of critical care in Bangladesh and India: What are the priority actions to promote person-centred care?

Patients’ experiences in the intensive care unit (ICU) can enhance or impair their subsequent recovery. Improving patient and family experiences on the ICU is an important part of providing high quality care. There is little evidence to guide how to do this in a South Asian critical care context. This study addresses this gap by exploring the experiences of critically ill patients and their families in ICUs in Bangladesh and India. We elicit suggestions for improvements from patients, families and staff and highlight examples of practices that support person-centred care. This multi-site hospital ethnography was carried out in five ICUs in government hospitals in Bangladesh and India, selected using purposive sampling. Qualitative data were collected using non-participant observation and semi-structured interviews and analysed using reflexive thematic analysis. A total of 108 interviews were conducted with patients, families, and ICU staff. Over 1000 hours of observation were carried out across the five study sites. We identified important mediators of patient and family experience that span many different aspects of care. Factors that promote person-centred care include access to ICU for families, support for family involvement in care delivery, clear communication with patients and families, good symptom management for patients, support for rehabilitation, and measures to address the physical, environmental and financial needs of the family. This study has generated a list of recommendations that can be used by policy makers and practitioners who wish to implement person-centred principles in the ICU

Hydraulic performance of a porous pipe irrigation lateral made from recycled tyres

Irrigation systems are known for their low efficiencies. Efforts must be made to conserve water resource in view of a greater competition from domestic, industrial and other sectors of the economy. Since a micro irrigation system can achieve a very high application efficiency, it should be further explored even for supplemental irrigation in a humid tropical country like Malaysia. Porous pipe irrigation lateral is useful for both surface and subsurface applications. A subsurface installation saves more irrigation water, which would otherwise be lost through surface evaporation. However very little information is now available on the discharge uniformity and operating characteristics of the imported porous pipe currently available locally. This paper presents results of a study on hydraulic characteristics of a type of porous pipes manufactured from recycled tyres. As extruded membrane, the pipe allows water to pass through the pores of the wall at low pressures. The tiny openings are made automatically during the manufacturing process. Since it has regular openings, irrigation is localized in a wetted strip whether it is buried or laid on the ground surface. Pressure-discharge relationship, head loss and friction factor-Reynolds number relationship were evaluated. The porous pipe was tested with various pressure inputs for several different lengths to seek the average rates and discharge uniformity. The pipe acts as a lateral with multiple-emitters. The porous pipe was found to be very sensitive to pressure variation with discharge exponent near 1.0. The pipe friction loss was large since the inner wall was very rough compared to the normal polyethylene laterals and another type of porous pipe made from geotextile