193 research outputs found
Improved fallows in Eastern Zambia: history, farmer practice and impacts
Get PDF"The decline in soil fertility in smallholder systems is a major factor inhibiting equitable development in much of sub-Saharan Africa. Some areas fallow in order to strength soil fertility for later planting, but as populations increase, demand follows and continuous cropping becomes the norm and there is a reduction in yields. This case study summarizes the development of improved tree fallows by researchers and farmers in eastern Zambia to help solve the problem of poor soil fertility. Many farmers are finding that by using improved fallows, they can substitute relatively small amounts of land and labor for cash, which they would need to buy mineral fertilizer. The study has three phases: the historical background (phase 1); an assessment of problems, description of the technology, and how it was developed (phase 2); and how the improved fallows practices were disseminated and spread (phase 3). This paper will describe each phase, the goals, and results." Authors' AbstractSouthern Africa, africa south of sahara, Crop yields,
A Conversation with James Fallows
No full textGary Eichten, Minnesota Public Radio news editor-at-large and retired host, leads a conversation with James Fallows, author, national correspondent for The Atlantic and commentator for National Public Radio, at 8 p.m. Wednesday, April 17, in Pellegrene Auditorium, Saint John\u27s University.
The conversation is co-sponsored at the College of Saint Benedict and Saint John\u27s University by the University Chair in Critical Thinking, the Center for Global Education and the Asian Studies Program.
Fallows is based in Washington as a national correspondent for The Atlantic. He has worked for the magazine for nearly 30 years and in that time has lived in Seattle; Berkeley, Calif.; Austin, Texas; Tokyo; Kuala Lumpur; Shanghai and Beijing. He was raised in Redlands, Calif., received his undergraduate degree in American history and literature from Harvard, and received a graduate degree in economics from Oxford as a Rhodes Scholar.
In addition to working for The Atlantic, he spent two years as chief White House speechwriter for Jimmy Carter, two years as the editor of U.S. News & World Report and six months as a program designer at Microsoft. He is an instrument-rated private pilot. He also holds the chair in U.S. media at the U.S. Studies Centre at the University of Sydney, in Australia.
Fallows has been a finalist for the National Magazine Award five times and has won once. He has also won the American Book Award for nonfiction and a New York Emmy award for the documentary series Doing Business in China. He was the founding chairman of the New America Foundation. His two most recent books, Blind Into Baghdad (2006) and Postcards From Tomorrow Square (2009), are based on his writings for The Atlantic. His latest book, China Airborne, was published in 2012
Simultaneous interplanetary scintillation and Heliospheric Imager observations of a coronal mass ejection
Get PDFWe describe simultaneous Interplanetary Scintillation (IPS) and STEREO Heliospheric Imager (HI) observations of a coronal mass ejection (CME) on 16 May 2007. Strong CME signatures were present throughout the IPS observation. The IPS raypath lay within the field-of-view of HI-1 on STEREO-A and comparison of the observations shows that the IPS measurements came from a region within a faint CME front observed by HI-1A. This front may represent the merging of two converging CMEs. Plane-of-sky velocity estimates based on time-height plots of the two converging CME structures were 325 kms?1 and 550 kms?1 for the leading and trailing fronts respectively. The plane-of-sky velocities determined from IPS ranged from 420 ± 10 kms?1 to 520 ± 20 kms?1. IPS results reveal the presence of micro-structure within the CME front which may represent interaction between the two separate CME events. This is the first time that it has been possible to interpret IPS observations of small-scale structure within an interplanetary CME in terms of the global structure of the event
Harmonic reduction methods for electrical generation: a review
Get PDFThis paper provides a comprehensive literature review of techniques for harmonic related power quality improvement of electrical generation systems. An increasing interest in these aspects is due to the ever more stringent power quality requirements, deriving from new grid codes and compliancy standards, aimed at limiting waveform harmonic distortion at all points of the distribution network. Although a wealth of literature is available for such techniques, it has never been compiled into a handbook incorporating all the solutions aimed at both electrical machine and power systems engineers
James Fallows - National orrespondent for The Atlantic and Award Winning Writer
No full textPostcards from Tomorrow Square: Reports from China
A national correspondent for The Atlantic, James Fallows is one of America’s most respected journalists. Whether writing about politics, national security, the economy, or foreign policy, Fallows strives to do one thing: “Make the important interesting.” For his always-perceptive, sometimes-prescient writing, he has won the National Book Award, the American Book Award, and been a finalist for the National Magazine Award five times, winning once. Writing from China since 2006, he is now chronicling that country’s explosive growth and its staggering ramifications for America and the world.
Fallows has covered the major foreign policy stories of our time—from Iraq to North Korea to Iran to the Israeli-Palestinian conflict, and beyond. In his lectures, he delivers an unsparing look at the challenges to American foreign policy posed by our actions in various regions, how other countries perceive us, and how upheavals overseas will impact us.
In his more than 25 years working for The Atlantic, Fallows has been based in Washington, DC, Seattle, Berkeley, Austin, Tokyo, Kuala Lumpur, Shanghai, and now Beijing. In addition to working for The Atlantic, he has spent two years as chief White House speechwriter for Jimmy Carter, two years as the editor of US News & World Report, and as a program designer at Microsoft. He received his undergraduate degree in American history and literature from Harvard, and received a graduate degree in economics from Oxford.
In addition to his latest book, Postcards from Tomorrow Square: Reports from China, Fallows is also the author of Breaking the News, about the crisis facing contemporary news media, and Blind into Baghdad, about the lead-up to the War in Iraq (now required reading in many military programs).
Please also join us on Wednesday, February 17, for the Wright State University Honors Institute Symposium on Connecting with China.https://corescholar.libraries.wright.edu/archives_presidential_lecture_series/1036/thumbnail.jp
Power quality improvement by pre-computed modulated field current for synchronous generators
No full textAlthough power quality aspects of electrical machines have been extensively studied and investigated for a large number of years, room for improvement still exists in the field of classic, wound-field, synchronous generators. This paper proposes an innovative method of power quality improvement for single-phase synchronous generators in which the usual DC field current is replaced by a calculated current waveform. The optimised field current waveform is designed in such a way that harmonics created by the machine geometry and the winding configuration are significantly reduced
Is exercise training safe and effective for ALL heart failure patients: A retrospective service evaluation of a hospital based cardiac rehabilitation programme
Get PDFThe main purpose of this study was to investigate whether exercise training is safe and effective for all classifications of heart failure, female and elderly (70 years and above) heart failure patients and also those heart failure patients with significant co-morbidity. Much of the research into exercise training and heart failure has been carried out on middle aged men in NYHA II-III classification of heart failure who have no other significant co-existing conditions. This is not reflective of the population of heart failure patients in general. The cardiac rehabilitation records (n=1000) of heart failure patients who had attended an exercise programme at a hospital based NHS service over a period of ten years were retrospectively evaluated to investigate the safety and efficacy of exercise training. Analysis of baseline statistics and repeated outcome measures were used to investigate the significance of the service and to ascertain where similarities and differences lay with the research. 74% were male, the age range was 17-90 years and 52% of patients had one or more significant co-morbidity. The acute event incidence was recorded at four per 1000 patients. NYHA I patients, female, elderly heart failure patients and those with significant co-morbidity showed significant improvements in functional capacity and quality of life measures with exercise training (p< 0.05). However no conclusion on the effectiveness of exercise could be drawn for NYHA IV heart failure patients due to insufficient recorded data and reduced adherence to exercise sessions for this group. A hospital based exercise programme, therefore may not be the most appropriate setting for the NYHA IV patient. This study supports previous research of the benefit of exercise training in heart failure but broadens it further to show that exercise is safe for all heart failure patients and is also effective for all heart failure patients with the exception of NYHA IV patients where further investigation is needed
Identifying grass-legume bicultures to increase above and belowground biomass production and improve traditional fallows in crop rotations of the Andean Highlands
Get PDF2021 Spring.Includes bibliographical references.In the high Andes of Peru, intensification of crop rotation and agricultural land-use is reducing the practice and duration of traditional fallow (based on natural establishment of native vegetation). These fallows represent one of the main traditional soil management practices to sustain long-term productivity, while also providing key forage resources in these mixed crop-livestock systems. Improved forage-based fallows, with the intentional seeding of more productive annual and perennial forages, offer great potential for producing forage and contributing to soil restoration under intensified contexts; however, there remains a gap in knowledge about which plant species can best optimize tradeoffs between forage production and belowground inputs to support long-term soil fertility and contribute to the multifunctionality of Andean agroecosystems. To address this issue, a pot study was conducted with two contrasting soils to evaluate the above and belowground productivity of all possible grass-legume pairs involving five grasses (oat (Avena sativa), ryegrass (Lolium multiflorum), festulolium (Lolium x Festuca genera), brome grass (Bromus catharticus), and orchardgrass (Dactylis glomerata), and four legumes (vetch (Vicia dasycarpa ), red clover (Trifolium pratense), black medic (Medicago lupulina), and alfalfa (Medicago sativa)) in comparison to the performance of each species in monoculture. Grass-legume bicultures resulted in significant overyielding, producing 65% and 28% more total dry biomass and total N uptake on average than species in monoculture, respectively. Grass-legume shoot biomass production yielded 67% more compared to monocultures, while root biomass was on average 58% higher in bicultures than in monocultures. For aboveground biomass, production differences between grass-legume bicultures were significantly influenced by the species of legume present, while belowground biomass was more affected by the grass species present in the bicultures. Roughly 80% of the mixtures achieved a mean land equivalent ratio (LER) > 1.0. When examining total biomass production, the most successful bicultures were oat-vetch (LER=1.87), vetch-festulolium (LER=2.31), vetch-orchardgrass (LER=1.87), oat-red clover (LER=1.62), and red clover-ryegrass (LER=1.46). When examining partial LERs (the component of the LER attributed to each species), we found that overyielding in bicultures was mainly driven by increases in the biomass of the component grass species. Our findings suggest that mixtures of key functional species (e.g. grass and legume, annual and perennial species) offer greater promise in improved fallows compared to monocultures of the respective species. Additionally, I suggest that strategically designed improved fallow mixtures, with emphasis on perennial species that support long-term root inputs, can best support soil health and the multifunctionality of Andean agroecosystems
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