Developmental morphology, biomass yield and compositional differences among upland and lowland switchgrass (Panicum virgatum L.) ecotypes grown as a bioenergy feedstock crop

Sustainable and successful development of the bioenergy industry strongly depends upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) has been identified as a model lignocellulosic bioenergy crop in the U.S. Information regarding its growth and development is considered critical for making management decisions, production of high quality feedstock and to support simulation model calibration and subsequent analysis. In the first study (Chapter 2), we evaluated upland (‘Cave-in-Rock’, ‘Trailblazer’ and ‘Blackwell’) and lowland (‘Kanlow’ and ‘Alamo’) ecotypes of switchgrass for harvest management, morphological (phenology and leaf area index) and biomass yield differences. A field study was conducted near Ames, IA during 2012 and 2013. The experiment was laid out as randomized complete block design. Six in-season destructive biomass harvests were collected at approximately 2-week intervals each year. In both years, delaying harvest to later maturity increased biomass yield in all cultivars. Averaged over years lowland cultivars ‘Kanlow’ and ‘Alamo’ produced higher dry matter yield (6.31 and 5.98 tons ha-1, respectively) than upland ecotypes ‘Cave-in-Rock’, ‘Trailblazer’ and ‘Blackwell’ (5.89, 4.78 and 4.53 tons ha-1, respectively). Lowland cultivars had delayed reproductive development compared with upland ecotypes. The widely recommended cultivar in Iowa ‘Cave-in-Rock’ had the highest mean stage count and leaf area index at the end of both growing seasons, but did not produce the greatest biomass. There was a nonlinear relationship between MSC and biomass yield. However, the magnitude and form of the response was different between cultivars and from year to year. In the next study (Chapter 3), our objective was to quantify the chemical composition of switchgrass varieties as influenced by harvest management, and to determine if ecotypic differences exist among them. We found that delaying harvest increased cellulose, hemicellulose and lignin concentrations while decreasing nitrogen and ash concentrations in all varieties. On average, Kanlow had the highest cellulose and hemicellulose concentration (354 and 321 g kg-1 DM respectively), and Cave-in-Rock had the highest lignin concentration (33 g kg-1 DM). The lowest nitrogen and ash concentrations were observed in Kanlow (14 and 95 g kg-1 DM respectively). In general, our results indicate that delaying harvest until fall improves feedstock quality, and ecotypic differences do exist between varieties for important feedstock quality traits. The objective of the third and final study (Chapter 4), was to developed a new mechanistic model to describe switchgrass phenology with the objective to assist agronomists and on-going breeding programs. Switchgrass is sensitive to photoperiod. However, existing switchgrass phenology models rely on thermal time coupled with ad-hoc empirical modifications to account for the effects of photoperiod when the model is to be applied across a wide range of environments. Our model simulates four phases of switchgrass development (emergence to juvenile, juvenile to elongation, elongation to flowering and flowering to maturity). It uses daily temperature and site latitude as driving variables, contains five cultivar specific biological meaningful parameters, and two model constants (base and optimum temperature of 10 oC and 30 oC, respectively). Three of the cultivar specific parameters (a1, a2, a3) define the thermal optimum time needed to complete a phase and the other two parameters describe the critical photoperiod (pcrit) and the photoperiod sensitivity (psen). The model matched Iowa’s observations with a RMSE (relative mean square error) of 2.6 days for each cultivar or with 5.1 days error when average parameters by ecotype were used. The next step in our analysis was to generalize the model by providing estimates of the photoperiod effect, and for that we used diverse literature database. We found that pcrit was 13.5 h and 12.7 h for upland and lowland cultivars. By using these parameters the overall prediction ability of the model across representative sites in the U.S. had an 8.4 days error. This model can be a helpful tool for improvement and development of calibration protocols for other models and it can also serve as a template for the development of phenology models for other perennial grasse

MHD mixed convection flow of viscoelastic fluid embedded in porous medium

An analysis has been carried out to investigate the effect of magnetic field presence on the mixed convection boundary layer flow of viscoelastic fluid over a horizontal circular cylinder in a porous medium. The governing non-similar partial differential equations are transformed into dimensionless forms and then solved numerically using the Keller-box method. Some important parameters have been discussed in this study which include the Prandtl number (Pr), magnetic parameter (M), viscoelastic parameter (K), porosity parameter () and the mixed convection parameters (). The results show the values of the velocity decrease when the value of viscoelastic parameter increase and the reverse trend were observe for temperature profile. Numerical results of local skin friction as well as local Nusselt number are also presented in tabular form

Vacinação contra poliomielite no Balochistão: questões e desafios

Like the condition of security and governance, health is also a major concern for Pakistan and there is a large population on an already insufficient medical treatment structure to cater for. Amongst various other diseases prevalent in Pakistan Poliomyelitis is one of the key concerns of the country with respect to medical situation. This research investigates the reasons behind the rejection of polio drops in Balochistan; weaknesses and efficiency of the polio eradication campaign and effects of cross-border movement and its governance between Afghanistan and Pakistan on the efficacy of the campaigns. The findings suggest that illiteracy, lack of motivation, religious interpretations, governance and security are the major challenges to the polio campaigns in the context of Balochistan.Al igual que la condición de seguridad y gobernanza, la salud también es una preocupación importante para Pakistán y hay una gran población en una estructura de tratamiento médico ya insuficiente para atender. Entre otras enfermedades que prevalecen en Pakistán, la poliomielitis es una de las principales preocupaciones del país con respecto a la situación médica. Esta investigación busca las razones detrás del rechazo de las gotas de poliomielitis en Balochistán; debilidades y eficiencia de la campaña de erradicación de la poliomielitis y los efectos del movimiento transfronterizo y su gobernanza entre Afganistán y Pakistán sobre la eficacia de las campañas. Los hallazgos sugieren que el analfabetismo, la falta de motivación, las interpretaciones religiosas, el gobierno y la seguridad son los principales desafíos para las campañas de poliomielitis en el contexto de Balochistán.Como a condição de segurança e governança, a saúde também é uma grande preocupação para o Paquistão e há uma grande população em uma estrutura de tratamento médico já insuficiente para atender. Entre várias outras doenças prevalentes no Paquistão, a Poliomielite é uma das principais preocupações do país em relação à situação médica. Esta pesquisa investiga as razões por trás da rejeição de gotas de poliomielite no Baluchistão; fraquezas e eficiência da campanha de erradicação da poliomielite e efeitos do movimento transfronteiriço e sua governança entre o Afeganistão e o Paquistão sobre a eficácia das campanhas. As descobertas sugerem que o analfabetismo, a falta de motivação, as interpretações religiosas, a governança e a segurança são os principais desafios para as campanhas de pólio no contexto do Baluchistão

Pivô da Ásia: Repercussões Estratégicas para o Paquistão

One of the important debates in the post 9/11 global politics has been the growing significance of the Asia pacific region. The great powers of the world have understood that the future of world’s attention would be Asia pacific region. This is in line with the significant military, economic, technological and diplomatic achievements of the regions. As a result, the United States introduced its famous policy known as “the Asia pivot” that has serious implications on the region in general and Pakistan in particular. The article investigates the Asia pivot policy of USA that has changed the course of region’s security. This particular policy brought changes in inter-state relations, while for some it proved virtuous and for others it brought problems. Pakistan, a country that has long maintained smooth relations with China and need-base relations with America faced serious upshots post arrival of this policy. It remained with scant options and policies to deal with the new impediments. This article focuses on those impediments and challenges that Pakistan can face due to the changes in geopolitical setting of the region. It also tries to unfold the secrets of new breakups and patch up between different states and allies in such whirling scenario of the region.Uno de los debates importantes en la política global posterior al 11 de septiembre ha sido el creciente significado de la región de Asia-Pacífico. Las grandes potencias del mundo han entendido que el futuro de la atención mundial sería la región de Asia-Pacífico. Esto está en línea con los importantes logros militares, económicos, tecnológicos y diplomáticos de las regiones. Como resultado, Estados Unidos introdujo su famosa política conocida como "el pivote de Asia" que tiene serias implicaciones en la región en general y en Pakistán en particular. El artículo investiga la política de giro de Asia de EE. UU. Que ha cambiado el curso de la seguridad de la región. Esta política particular trajo cambios en las relaciones interestatales, mientras que para algunos resultó ser virtuosa y para otros trajo problemas. Pakistán, un país que ha mantenido durante mucho tiempo las relaciones fluidas con China y las relaciones basadas en la necesidad con los Estados Unidos, enfrentó serias oportunidades después de la llegada de esta política. Se mantuvo con escasas opciones y políticas para enfrentar los nuevos impedimentos. Este artículo se enfoca en los impedimentos y desafíos que Pakistán puede enfrentar debido a los cambios en el entorno geopolítico de la región. También trata de revelar los secretos de nuevas rupturas y parchear entre diferentes estados y aliados en un escenario tan arrollador de la región.Um dos debates importantes na política global pós-11 de setembro tem sido o crescente significado da região Ásia-Pacífico. As grandes potências do mundo entenderam que o futuro da atenção do mundo seria a região Ásia-Pacífico. Isto está de acordo com as significativas conquistas militares, econômicas, tecnológicas e diplomáticas das regiões. Como resultado, os Estados Unidos introduziram sua famosa política conhecida como “pivô da Ásia”, que tem sérias implicações na região em geral e no Paquistão em particular. O artigo investiga a política de pivô da Ásia dos EUA que mudou o curso da segurança da região. Essa política específica trouxe mudanças nas relações interestaduais, enquanto, para alguns, mostrou-se virtuosa e, para outros, trouxe problemas. O Paquistão, um país que há muito mantém relações tranquilas com a China e relações de necessidade com os Estados Unidos, enfrentam sérios resultados após a chegada dessa política. Permaneceu com poucas opções e políticas para lidar com os novos impedimentos. Este artigo concentra-se nos impedimentos e desafios que o Paquistão pode enfrentar devido às mudanças no cenário geopolítico da região. Ele também tenta desdobrar os segredos de novas dissidências e remendos entre diferentes estados e aliados em um cenário tão agitado da região

Effect of partial slip on an unsteady MHD mixed convection stagnation-point flow of a micropolar fluid towards a permeable shrinking sheet

AbstractThe objective of the present study was to investigate the partial slip effect on an unsteady two-dimensional mixed convection stagnation point flow towards a permeable shrinking sheet. The governing equations are reduced to a system of non-dimensional partial differential equations using a semi-similarity transformation, before being solved numerically by using Keller-box method. The features of the flow characteristics for different values of the governing parameters are analysed and discussed. The results indicate that the momentum, thermal and concentration boundary layer thicknesses increase with increasing mixed convection parameter for opposing flow, whereas the opposite effect is observed for assisting flow. The results also show that the surface velocity is higher when there is slip at a sheet compared to its absent. Further, the study indicates that the boundary layer thicknesses become thicker and thicker with increasing shrinking parameter, while the opposite effect is observed with increasing Hartmann number. Comparison with previously published work for special cases is performed and found to be in excellent agreement

MHD Stagnation-Point Flow of a Nanofluid with Heat and Mass Transfer in the Presence of Thermal Radiation

The steady two-dimensional magnetohydrodynamics stagnation point flow of a nanofluid with radiation effect is investigated. Using a similarity transformation, the governing partial differential equations are reduced to ordinary differential equations. The transformed equations are solved numerically for three types of nanoparticles, namely copper (Cu), alumina (Al2O3), and titania (TiO2) by using shooting method. The features of the flow with heat and mass transfer characteristics for different values of governing parameters are analyzed and discussed. Comparison with published results is presented and it found to be in good agreement. Key Words: Nanofluid, Heat and Mass Transfer, Thermal Radiation, Stagnation-Point Flo

The Analysis of Queuing Theory Process for Customer Services Delivery: A Case Study of MUET Examination Department Jamshoro.

The application of Queuing models as technique of Queue solution in issuing the certificates like (pass certificates, marks certificates, transcript and Degree) in examination department MUET, Jamshoro. Specially this study attempts to look at the problem of long Queues in Examination department MUET Jamshoro. The variables measured include arrival rate (λ) and service rate. The were analyzed for the data of April 2017 to May 2018 and the efficiency in students satisfactory through the use of multichannel queuing models which were compare for a number of queue performance. It was discovered that using a 11- server channel system was better than a 9-serrver model,7-serrver model, 5-serrver model, 3-serrver model and 2-server model. Keywords: students issuing certificates, multichannel Queuing Model, server efficiency, Queue Length, Queue Time

10thannual neurology research day, may 2016 abstracts shifa international hospital, islamabad

Burden of headache has been assessed in adults in countries worldwide, and is high, but data for children and adolescents is sparse. The objective of this study is to fill the information gap for adolescents

Developmental Morphology and Biomass Yield of Upland and Lowland Switchgrass Ecotypes Grown in Iowa

Sustainable development of the bioenergy industry will depend upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) is a model lignocellulosic bioenergy crop but critical information is lacking for improved management, growth, and development simulation model calibration. A field study was conducted near Ames, IA during 2012–2013 with the objective to evaluate upland (“Cave-in-Rock”, ‘Trailblazer’ and ‘Blackwell’) and lowland (“Kanlow” and “Alamo”) switchgrass ecotypes for harvest timing on morphology (i.e., phenology, leaf area index (LAI), and biomass yield). The experiment used a randomized complete block design, with three upland and two lowland varieties harvested at six dates annually. In both years, delaying harvest to later maturity increased biomass yield; lowland cultivars produced greater biomass yield (6.15 tons ha−1) than upland ecotypes (5.10 tons ha−1). Lowland ecotypes had delayed reproductive development compared with upland ecotypes. At the end of both growing seasons, upland ecotypes had greater mean stage count (MSC) than lowland ecotypes. “Cave-in-Rock” had greatest MSC and LAI, but did not produce the greatest biomass. Relationships were nonlinear between MSC and biomass yield, with significant cultivar–year interaction. The relationship between biomass yield and MSC will be useful for improving switchgrass, including cultivar selection, fertilizer application, and optimum harvest time