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Optimizing Tillage and Irrigation Requirements of Sorghum in Sorghum-Pigeonpea Intercrop in Hamelmalo Region of Eritrea

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Journal of Geoscience and Environment Protection 2016年第4期4卷 63-73页

作者： Tesfalem Weldeslassie ramesh prasad tripathi Woldeselassie Ogbazghi Department of Land Resources and Environment Hamelmalo Agricultural College Keren Eritrea

Sorghum (Sorghum bicolor L. Moench) is cultivated as monocrop in Eritrea. Efforts were made to grow sorghum-pigeonpea (Cajanus cajan L. Millspp.) intercrop on the tillage, fertilizers and supplementary irrigations necessary for sorghum. Experiments were conducted in terraced fields at Hamelmalo during 2013-15 to evaluate growth and yield of sorghum-pigeonpea intercrop in split plot design with conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) in main plots and rainfed (I0), 50% of full irrigation (I1), 75% of full irrigation (I2) and 100% of full irrigation (I3) in subplots. All irrigations were stopped 15 days before sorghum maturity. Full irrigation was 60 mm applied at 50% depletion of available soil water in 1 m profile. Sorghum growth was faster than pigeonpea until 85 days from planting and pigeonpea growth accelerated only after sorghum harvesting. About 80% of sorghum roots were within 0.6 m profile but more than 75% of pigeonpea roots were below 0.60 m depth. This showed a weaker competition between the two crops for nutrients, water and light. Both grain and stover yields of sorghum were optimum in RT + I2 during the 2 years. Highest grain yield was 6900 kg·ha-1 in RT + I3 in 2013, which was at par with that in RT + I2. Mean residual soil moisture at sorghum harvesting was 74 mm·m-1, which decreased to 8 mm·m-1 by pigeonpea harvesting. Residual moisture was more in the irrigated than non-irrigated plots. Pigeonpea yields were optimum (1363 kg·ha-1) in RT + I3 and lowest (297 kg·ha-1) in ZT + I0. Average water use by sorghum-pigeonpea was 374 mm by sorghum harvesting and 438 mm by pigeonpea harvesting, producing total sorghum equivalent yield of 7475 kg·ha-1. This raised average water use efficiency from 12.6 kg·ha-1·mm-1 at sorghum harvesting to 17.1 kg

关键词： Residual Soil Moisture Sorghum-Pigeonpea Intercrop Supplementary Irrigation Water Use Efficiency

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Irrigation and Nitrogen Requirements of Wheat under Shallow Water Table Conditions of Asmara, Eritrea

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Journal of Geoscience and Environment Protection 2016年第4期4卷 80-87页

作者： Fekadu Tesfamichael ramesh prasad tripathi Mehreteab Tesfai Department of land Resources and Environment Hamelmalo Agricultural College Keren Eritrea

Wheat (Triticum astivum L.) is traditionally rainfed in Eritrea. Yields are low because of poor soil management and low water and nutrient inputs. A field experiment was conducted in Akria farm, located in the outskirts of Asmara. The soil was clay loam associated with non-saline shallow water tables fluctuating from 0.4 to 1.2 m depths during the crop season. Wheat variety Wedel Nile was planted in split plot design with four levels of supplementary irrigations (SI) viz. I1 (rainfed, 0 SI), I2 (1/3 of full SI), I3 (2/3 of full SI), and I4 (full SI) in main plots and three levels of nitrogen viz. N1 (18 kg N haǃ), N2 (50 kg N haǃ), and N3 (100 kg N haǃ) as sub-plots in three replications. Full SI refers to amount of water necessary to replenish soil moisture deficit in the root zone from field capacity to 50% depletion of the available soil moisture. Groundwater table was constant around 0.4 m depth for 32 days from planting and declined slowly thereafter. Wetness around 0.3 m depth was thus near field capacity until second week of December and reduced thereafter with declining water table. Average soil moisture depletion was 94 mm under rainfed and 64 mm under full irrigation. No symptoms of wilting were observed in any of the treatments due to shallow water tables. Upward flux from the water table was 4.6 mm·d-1 until 30 days from planting, which declined to 0.2 mm·d-1 when the water table declined below 0.9 m depth. Optimum yield of wheat (5603 kg·ha-1) was obtained by application of 58 mm irrigation (I3) and 100 kg·ha-1 nitrogen (N3). Total water use for optimum yield of wheat was 382 mm and water use efficiency was 14.7 kg·ha-1·mm-1. Contribution from water table to the evapotranspiration requirements of wheat was highest (61%) under rainfed (I1

关键词： Evapotranspiration Nitrogen Supplementary Irrigation Water Table Contribution Water Table Wheat

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Rice Production Prospects in Eritrea

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Journal of Water Resource and Protection 2015年第17期7卷 1429-1434页

作者： ramesh prasad tripathi Woldeselassie Ogbazghi Semere Amlesom Department of Land Resources and Environment Hamelmalo Agricultural College Keren Eritrea

Rice is not cultivated in Eritrea because of its high water requirements and arid to semiarid conditions. However, most agricultural watersheds in Eritrea are associated with >80% non-agricultural lands, which produce significant runoff that can be diverted for use by rice crop. Experiments were conducted at Hamelmalo Agricultural College, Eritrea, using four NERICA rice varieties viz. N1, N4, N10 and N11 under rainfed (Io) and limited supplementary irrigations (I) in 3 replications. Results showed that plants were taller under limited irrigations than rainfed. Among the 4 varieties, N11 was most affected by water stress in which plant height was 0.72 m under rainfed and 0.89 m under limited irrigations. Effective tillers were highest (6) in N11 under limited irrigations and lowest (2) in N10 under rainfed. Panicles were shorter (0.20 m) in N10 and longer (0.23 - 0.24 m) in N1 and N11. Irrigations delayed maturity by 6 - 15 days. Water use by N11 was higher both under limited irrigations (987 mm) and rainfed (477 mm) and lower by N10 under rainfed (457 mm). Root growth in all the varieties was better under irrigations (I) than rainfed (Io). Roots were limited to 0.7 m depth under rainfed (Io) but grew down to 0.8 m in N1, N4 and N11 under limited irrigations (I). Roots in N10 were limited to 0.5 m depth under Io and 0.7 m under I. More than 63% roots in N10 were in 0 - 0.1 m layer under rainfed as against less than 55% under limited irrigations. In lower layers, roots under Io were more in N4 than others, which is a beneficial trait for better performance under semiarid environments. Roots in N11 were better and uniformly distributed in lower layers under irrigated conditions. Rooting patterns and grain yields showed that N11 was most responsive to irrigations but susceptible to water stress and N4 was best under rainfed followed by N10. N4 was next to N11 under irrigated conditions.

关键词： Irrigated and Rainfed Rice NERICA Rice Eritrea Root Growth Water Use Yield

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Effect of Puddling and Compaction on Water Requirements of Rice at Hamelmalo, Eritrea

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Computational Water, Energy, and Environmental Engineering 2016年第2期5卷 27-37页

作者： Bahlbi Goitom ramesh prasad tripathi Woldeselassie Ogbazghi Tesfalem Weldeslassie Department of Land Resources and Environment Hamelmalo Agricultural Colleg Keren Eritrea

Eritrean farmers can cultivate rice by harvesting runoff from >82% available non-agricultural land in agricultural watersheds for crop use and reducing percolation through optimization of tillage. Experiments were conducted with NERICA rice, N11, to optimize irrigation requirements and puddling and compaction to reduce percolation. Experimental field was adjacent to Anseba River at downstream end of the watershed and a pond on the upstream to intercept runoff. Irrigation treatments were runoff farming with maximum runoff application depth of 10 mm (I1), and 50 mm irrigation two (I2), five (I3), and seven (I4) days after disappearance of ponded water in main plots and puddling by one (T1), two (T2) and three (T3) passes of puddler and compaction by three (T4), four (T5) and five (T6) passes of 600 kg roller in sub plots in 3 replications. Soil profile was loam in the surface 0.45 m and coarse sandy loam below forming porous belt. Soil submergence was difficult to maintain, but water table was developed in soil profile due to inflow of seepage from the river and pond. Depth to the water table was within 1.5 ± 0.1 m for >2 months and receded down to 1.7 m by crop maturity. Soil wetness was near field capacity around 0.7 m depth and increased below due to natural sub-irrigation from the water table. Rice roots penetrated 0.8 m in the puddled plots and 0.7 m in the compacted plots. Residual soil moisture of 135 - 146 mm·m-1 after rice harvesting provides opportunity for planting rapeseed mustered following rice. Puddling was superior to compaction in loam soil. Puddling twice and irrigation 50 mm 7 days after ponded water vanished from surface was sufficient for optimum rice grain yield of 4346 kg·ha-1 and straw yield of 4458 kg·ha-1. Optimum puddling and irrigation schedules reduced crop duration by 6 days without significantly a

关键词： Compaction Irrigation NERICA Rice Puddling Runoff Farming Water Table

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Runoff Harvesting and Storage for Rice Crop at Hamelmalo, Semiarid Region of Eritrea

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Computational Water, Energy, and Environmental Engineering 2016年第1期5卷 1-9页

作者： ramesh prasad tripathi Woldeselassie Ogbazghi Semere Amlsom Simon Measho Department of Land Resources and Environment Hamelmalo Agricultural College Keren Eritrea

Rice is staple food in Eritrea but it is not cultivated in the country due to semiarid conditions. However, possibilities exist for growing rice using runoff produced from nonagricultural hilly lands, which occupy >50% - 80% area of all agricultural watersheds in Eritrea. Study was undertaken in 6 ha watershed at Hamelmalo to design and develop waterway for safe harvesting of runoff from 5.5 ha catchment into a pond for facilitating runoff farming of rice in 0.5 ha field at the outlet end receiving recurrent floods. Slope of the catchment ranged from 1% to 6%. The waterway was designed to intercept and carry runoff from two major drains in nonagricultural land together and delivering into a pond made adjacent to rice field. The waterway was about 323 m long with 3 m top width, 1.5 m bottom width and 0.3 - 0.8 m depth from surface. The pond was 60 m long, 9 m wide and 1 m deep with 1.5 m high earthen dam towards rice field using soil excavated from the pond. Embankment on the remaining sides was mango orchard land slopping towards pond. The dam base width was 4 m, top width was 2.5 m and height was 1.5 m from the ground surface. Two spill ways were provided in the dam at ends at the ground level to facilitate release of runoff from the pond for irrigation. Gross capacity of pond was >1000 m3. Combined effect of river water, percolation from pond and wetter rice field raised groundwater table from 3.25 m depth in June to 1.4 m by mid-crop season. This resulted in soil wetness exceeding field capacity below 0.7 m depth and greener crop. Rice yields exceeding 2000 kg·ha-1 were harvested under runoff farming conditions. Soil puddling was more conducive to rice crop than compaction under available soil and water resources.

关键词： Compaction Pond Puddling Rice Runoff Farming Waterway

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Fabrication and functional characterization of engineered features on pyrolytic carbon

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Advances in Manufacturing 2016年第2期4卷 134-141页

作者： Vivek Bajpai Bablu prasad ramesh Singh Department of Mechanical Engineering Indian Institute ofTechnology Bombay Powai Mumbai 400076 India Centre for Environmental Science and Engineering IndianInstitute of Technology Bombay Powai Mumbai 400076India

Engineered features on pyrolytic carbon （PyC） have been reported to improve the functional performance of the bio-implants. This paper is focused on the functional characterization of micro-features created on the surface of PyC. Two different types of micro-features （wide channels and arrayed holes） have been created by micro-electrical discharge machining （micro-EDM）. Two other micro-fea- tures （fine channels and micro-pillars） have been created by micromilling process. Coliform bacterial strain was iso- lated from a sample of water and grown on all four tex- tured. Cell growth was carried out on an unmachined surface to see the behavior of the isolated bacterial strain on the textured/non-textured surfaces. The samples were examined under SEM before and after wash to see cell growth and cell adhesion capability of the textures. The wide channels by micro-EDM show the maximum cell growth but poor cell adhesion. 184% higher cell growth has been observed on the wide channels in comparison with unmachined surface. The fine channels by micro-milling show comparatively lower growth but the cell adhesion on this surface was found excellent. 71% cells remain unwa- shed after washing of the surface having fine channel textures. It means that the channels structure shows the maximum cell growth and adhesion independent of machining process.

关键词： Pyrolytic carbon Micro-features Surfacetexturing Cell growth and adhesion

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Cilia-assisted hydromagnetic pumping of biorheological couple stress fluids

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Propulsion and Power Research 2019年第3期8卷 221-233页

作者： K.ramesh D.tripathi O.Anwar Bég Department of Mathematics Symbiosis Institute of TechnologySymbiosis International UniversityPune412115India Department of Mechanical Engineering Manipal University JaipurRajasthan303007India Fluid Mechanics/Propulsion Aeronautical/Mechanical Engineering DepartmentSalford UniversityManchesterUK

A theoretical study is conducted for magnetohydrodynamic pumping of electroconductive couple stress physiological liquids(***)through a two-dimensional ciliated channel.A geometric model is employed for the cilia which are distributed at equal intervals and produce a whip-like motion under fluid interaction which obeys an elliptic trajectory.A metachronal wave is mobilized by the synchronous beating of cilia and the direction of wave propagation is parallel to the direction of fluid flow.A transverse static magnetic field is imposed transverse to the channel *** Stokes’couple stress(polar)rheological model is utilized to characterize the *** normalized two-dimensional conservation equations for mass,longitudinal and transverse momentum are reduced with lubrication approximations(long wavelength and low Reynolds number assumptions)and feature a fourth order linear derivative in axial velocity representing couple stress contribution.A coordinate transformation is employed to map the unsteady problem from the wave laboratory frame to a steady problem in the wave *** slip conditions are imposed at the channel *** emerging linearized boundary value problem is solved analytically and expressions presented for axial(longitudinal)velocity,volumetric flow rate,shear stress function and pressure *** flow is effectively controlled by three geometric parameters,viz cilia eccentricity parameter,wave number and cilia length and two physical parameters,namely magnetohydrodynamic(MHD)body force parameter and couple stress non-Newtonian *** solutions are numerically evaluated with MATLAB *** velocity is observed to be enhanced in the core region with greater wave number whereas it is suppressed markedly with increasing cilia length,couple stress and magnetic parameters,with significant flattening of profiles with the latter two *** pressure gradient is decreased with eccentricity parameter whereas it is ele

关键词： Magneto hydrodynamics Metachronal waves Cilia Synchronous beating Polar couple stress fluid Physiological transport Magnetic blood pumps

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Field cancerisation in colorectal cancer:A new frontier or pastures past?

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World Journal of Gastroenterology 2015年第13期21卷 3763-3772页

作者： Abhilasha Patel Gyanendra tripathi Kishore Gopalakrishnan Nigel Williams ramesh P Arasaradnam Department of Colorectal Surgery University Hospitals of Coventry and Warwickshire NHS TrustCoventry CV2 2DXUnited Kingdom University of Warwick Coventry CV4 7ALUnited Kingdom Department of Pathology University Hospitals of Coventry and Warwickshire NHS TrustCoventry CV2 2DXUnited Kingdom

Despite considerable advances in our understanding of cancer biology, early diagnosis of colorectal cancer remains elusive. Based on the adenoma-carcinoma sequence, cancer develops through the progressive accumulation of mutations in key genes that regulate cell growth. However, recent mathematical modelling suggests that some of these genetic events occur prior to the development of any discernible histological abnormality. Cells acquire pro-tumourigenic mutations that are not able to produce morphological change but predispose to cancer formation. These cells can grow to form large patches of mucosa from which a cancer arises. This process has been termed "field cancerisation". It has received little attention in the scientific literature until recently. Several studies have now demonstrated cellular, genetic and epigenetic alterations in the macroscopically normal mucosa of colorectal cancer patients. In some reports, these changes were effectively utilised to identify patients with a neoplastic lesion suggesting potential application in the clinical setting. In this article, we present the scientific evidence to support field cancerisation in colorectal cancer and discuss important limitations that require further investigation. Characterisation of the field defect is necessary to enable early diagnosis of colorectal cancer and identify molecular targets for chemoprevention. Field cancerisation offers a promising prospect for experimental cancer research and has potential to improve patient outcomes in the clinical setting.

关键词： Colorectal cancer Carcinogenesis Biomarkers Epigen

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Recent advances in new-onset diabetes mellitus after kidney transplantation

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World Journal of Diabetes 2021年第5期12卷 541-555页

作者： Tess Montada-Atin G V ramesh prasad Kidney Transplant Program St.Michael's HospitalToronto M5C 2T2OntarioCanada Department of Medicine University of TorontoToronto M5C 2T2Canada

A common challenge in managing kidney transplant recipients(KTR)is posttransplant diabetes mellitus(PTDM)or diabetes mellitus(DM)newly diagnosed after transplantation,in addition to known pre-existing *** is an important risk factor for post-transplant cardiovascular(CV)disease,which adversely affects patient survival and quality of *** disease in KTR may manifest as ischemic heart disease,heart failure,and/or left ventricular *** therapies for PTDM include most agents currently used to treat type 2 *** recently,the use of sodium glucose co-transporter 2 inhibitors(SGLT2i),glucagon-like peptide-1 receptor agonists(GLP-1 RA),and dipeptidyl peptidase 4 inhibitors(DPP4i)has cautiously extended to KTR with PTDM,even though KTR are typically excluded from large general population clinical *** evidence from observational studies seems to indicate that SGLT2i,GLP-1 RA,and DPP4i may be safe and effective for glycemic control in KTR,but their benefit in reducing CV events in this otherwise high-risk population remains *** newer drugs must still be used with care due to the increased propensity of KTR for intravascular volume depletion and acute kidney injury due to diarrhea and their single-kidney status,pre-existing burden of peripheral vascular disease,urinary tract infections due to immunosuppression and a surgically altered urinary tract,erythrocytosis from calcineurin inhibitors,and reduced kidney function from acute or chronic rejection.

关键词： Cardiovascular disease Glucagon-like peptide-1 receptor agonists Kidney transplantation Oral antihyperglycemic drugs Post-transplant diabetes mellitus Sodium glucose co-transporter 2 inhibitors Dipeptidyl peptidase-4 inhibitors

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Microstructure and texture evolution in AZ31 magnesium alloy during caliber rolling at different temperatures

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Journal of Magnesium and Alloys 2017年第3期5卷 340-347页

作者： Abhishek tripathi S.V.S.Narayana Murty P.ramesh Narayanan Department of Metallurgical Engineering and Materials Science Indian Institute of Technology BombayMumbai 400076India Materials Characterisation Division Materials and Metallurgy GroupVikram Sarabhai Space CentreTrivandrum 695022India

Magnesium alloy AZ31 was caliber rolled at different temperatures viz.523K,573K,623K,673K and 723K imposing a total cumulative reduction of 92%and a cumulative strain of *** associated microstructure and texture evolution were studied using Electron Back Scattered Diffraction(EBSD)and X-ray macro-texture observations *** refinement was observed in all the caliber rolled bars indicating the occurrence of dynamic *** parameter and texture index were used to study the evolution of *** doubling of the yield strength at room temperature was observed by caliber rolling at a temperature of *** improvement in mechanical properties was explained on the basis of the fine grain microstructures and suitable development of crystallographic *** on the present study,warm caliber rolling can be used as a good production method for obtaining long bars of high strength magnesium alloy AZ31.

关键词： Magnesium alloy AZ31 Microstructure Caliber rolling Texture

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