Experimental Study of Moisture Effect on the Nanofiber Z-Threaded Carbon Fiber Reinforced Polymer Prepreg and Its Composite

A persistent issue found in Carbon Fiber Reinforced Polymer (CFRP) manufacturing is moisture contamination. During manufacturing, this issue is present when a CFRP prepreg is carefully thawed, cut, stacked, and cured into the desired laminate. The moisture affects the structural integrity of the finished laminate and can present as voids. Recent advancements in carbon nanofiber (CNF) z-threaded CFRP (i.e., ZT-CFRP) prepreg have yielded laminates that have significant multifunctional improvements in, but are not limited to, mechanical strength, toughness, thermal conductivity, and electrical conductivity. This approach affects the microstructure of the laminate in which the CNF interlocks with the carbon fiber along the through-thickness direction (i.e., Z-direction) giving an effective 3D-fiber-network reinforced laminate. In this study, the impact of relative humidity (RH) on the interlaminar shear strength (ILSS) and the hardness of ZT-CFRP and traditional CFRP prepregs during handling and lamination processes are investigated. The microscopic analysis will aid in explaining how different moisture conditions affect the sample laminates. ILLS testing provides a glimpse into how the different moisture conditions affect the ZT-CFRP and the CFRP laminates

I. Palladium (0)-Catalyzed Asymmetric Rearrangement of Allyl Enol Ether for the Synthesis of Α -aryl Quaternary Carbon Center. II. Synthesis of Chiral Tryptophan Analogs and Studies Towards Synthesis of Tryprostatin A and B

The development of efficient catalytic enantioselective synthesis of all carbon quaternary centers is a significant challenge in chemical synthesis due to the difficulties of carbon-carbon bond formation at quaternary center. Using phase transfer catalyst we attempted to create quaternary carbon center via direct C-alkylation of hydroxyarylacrylates, instead we obtained O-alkylated acrylates. We succeeded in C-alkylation which involves an indirect method via the O-alkylation of 3-hydroxy aryl acrylates and a subsequent [3, 3] sigmatropic rearrangement (Claisen rearrangement). The O-alkylated products are obtained in yields ranging from 65-85%, and the corresponding Claisen rearrangement products in yields ranging from 55-90%. Typically Pd(II) catalysts are used for this type of transformation. But several attempts at accomplishing an asymmetric Claisen rearrangement using metal Lewis acid catalysis failed due to insufficient activation of the Claisen substrate. Herein, we report the creation of all carbon stereocenters starting from 3-hydroxyarylacrylates modified allyl enol ether rearrangement reaction. We believe this is the first example of allyl enol ether rearrangement employing Pd(0) catalysts. The rearrangement reaction analogs takes place in excellent yields ranging from 80-95% and enantioselectivity ranging from 50-90% ee. Asymmetric synthesis of indole alkaloids is a major area in organic synthesis. Synthesis of chiral Tryptophans and its unnatural analogs has immense importance as they are building blocks for many natural products. Herein we describe the enantiospecific synthesis of ring-A substituted tryptophan derivatives from commercially available gramines using chiral phase transfer conditions. This one-pot reaction avoids protecting/de-protecting the indolylic nitrogen of gramine by choosing a chemoselective quaternization reagent, 4-(trifluoromethoxy)benzyl bromide to produce an electrophilic salt intermediate, which is subsequently alkylated in good yield and high %ee. In an application of chiral tryptophans we attempted to synthesize tryprostatins. Tryprostatins are potent cancer drug, tryptostatin A reverses the resistance of cancer cells against antitumor drugs by arresting cell cycle progression at the G2/M phase. We have been able to make tryprostatin B using our proposed synthesis scheme, where one of the key intermediate is C-2 alkylated chiral tryptophan. Several challenges in the synthesis protocol and optimization of the chiral phase transfer catalyzed reaction are described

Responses of plant species diversity and soil physical-chemical-microbial properties to Phragmites australis invasion along a density gradient

Abstract The invasion of ecosystems by strongly colonising plants such as Phragmites australis is viewed as one of the greatest threats to plant diversity and soil properties. This study compared a range of diversity measures including soil properties and mycorrhizal potential under different degrees of Phragmites density among three populations in coastal wetland, Victoria, Australia. Species richness, evenness and Shanon-Wiener index had significantly higher values in low degree of Phragmites density in all populations. Higher densities had the lowest diversity, with Shannon-Wiener index = 0 and Simpson’s index = 1 indicating its mono-specificity. Significant alterations in soil properties associated with different degrees of Phragmites density were noticed. These had interactive effects (population × density) on water content, dehydrogenase activity, microbial biomass (C, N and P) but not on pH, electrical conductivity, phenolics, organic carbon, and spore density. Furthermore, the study elucidated decrease of competitive abilities of native plants, by interfering with formation of mycorrhizal associations and biomass. Overall, our results suggest that significant ecological alterations in vegetation and soil variables (including mycorrhizal potential) were strongly dependent on Phragmites density. Such changes may lead to an important role in process of Phragmites invasion through disruption of functional relationships amongst those variables

Nutrient limitation and stable nitrogen isotope ratios in two plOneer species Robinia pseudoacacia and SalLx: gilgiana colonized on the nutrient poor sediment barof a regulated river

Flow regulation through dam construction in the upstream of large rivers enables the colonization of vegetation on the downstream sediment bar with organic matter acctunulation and silt trap. Robinia pseudoacacia, a woody legume and Salix gilgiania, a nood-tolerant shnlb colonize on the mid-stream sediment bar where soil nutrient levels are relatively low. This two species can colonize along the gradients of the sediment bar withdistinct soil characteristics. Total nitrogen (TN) to total phosphorus (TP) ratios has been widely used as diagnostic indicators of nitrogen saturation and limitation of plant growth. Samples of above-ground organs, roots and soils were collected and analyzed. High TN content was found in nodule followed by leaf, rootand then shoot tissue of. pseudoacacia whereas in S, gilgiania, it was the highest in leaf followed by shoot and the root tissue.TP content was found high in the leaf tissues of both species. High ratio of nitrogen and phosphorus in the tissue of R.pseudoacacia indicating that plant growth is P limited whereas the ratio was very low in the soil samples. The growth of S. gilgiania is nitrogen limited as the N and P ratio in the plant tissues was low. Mean nitrogen stable isotope ratio 815N in S. gilgiania was relatively higher thanthe R. pseudoacacia. Nitrogen sattlration in the tissues of R. pseudo-acacia occurs asthe symbiotic bacteria fix atmospheric nitrogen.Article信州大学山地水環境教育研究センター研究報告 6: 35-42(2010)departmental bulletin pape

Seasonal dynamics of soil macro- and micronutrients and phenolics under kudzu (Pueraria lobala) stands in fLoodplain of a modirledriver

Kudzu (Pueraria lobata) is a rapidly spreading liana inthe noodplain of Tama River, Japan. This species is veryrich in secondary metabolites and adds substantial amount of litter into the soil due to its huge biomass tumover in every growing Cycle. This study aims to investigate the seasonal dynamics of major macro- and micronutrients and phenolics in soil associated with the litter productionand growth ofkudzu plants in the downstream of Tama River. Soils were collected &om three kudzu-infested spots alongthe banks of the river and analyzed for total carbon, total nitrogen, total phosphoms, potassium, copper, zinc, sodium and phenolic contents･ The pattems of seasonal changes of those soil elements in all three spots were more or less similar. The levels of the nutrients were related with the growth stages or kudzu plants･ Concentrations of all nutrients except nitrogen went down when the kudzu was at active vegetative stage･ The nutrients were agalnmineralized into the soil after the decomposition ofkudzu litter at winter season･ Soil phenolic contentumder kudzu stand also varied seasonally and the highest quantity was recorded in winter as an outcome ofkudzu litter decomposition･ Soil phenolics was not found to interfere the chemical properties of soil except K, of which concentration in soil was negatively correlated with that of soil phenolics･Article信州大学山地水環境教育研究センター研究報告 6: 43-54(2010)departmental bulletin pape

The Association between Project Success and Project Initiation Phase: A Study on Some Selected Projects in Bangladesh

The purpose of this study is to examine empirically the association between the different phases of project initiation process and the project success in the environment of Bangladesh. The study samples 50 companies, local and foreign, operating in real estate, garments, and electronics sector in Bangladesh. The result of the study indicates that most of the factors in the project initiation process have significant positive relationship to the project success other than project taken based on opportunity and feasibility study done by specialized firms. The study is important to managers, policymakers, and academics as it demonstrates which factors of project initiation process contribute significantly to the successful completion of a project. There is no research on the association between the different phases of project initiation process and the project success in Bangladesh. This study extends the literature by demonstrating the impact of different phases of project initiation process on project success. Key Words: Project Success; Business Case; Project Initiation; Project office; Project Phase review

Adoption and Usage of Web-based Library Resources and Services: an Investigation of icddr,b Library in Bangladesh

Purpose – The core purpose of this study is to explore the web-based library services available in icddr,b Library. In addition, this research aims to investigate the adoption and utilisation of subscribed, registered and open access e-resources by the scientists and researchers at icddr,b Library. The existing facilities that influenced smooth usage of web-based information services of icddr,b library have been assessed. The study involved scientists and researchers of icddr,b. Design/methodology/approach – The study used a mixed-method research design using case study approach. Both qualitative and quantitative approaches were used. An online survey was conducted in June 2017 to ascertain the present status of web-based library facilities and services of icddr,b library. The online survey questionnaire link was distributed through “Google Forms” directed to the most potential researchers (557) of icddr,b. Findings – The findings revealed that participants were moderately aware of the library subscribed and registered e-resources. The study also explored key challenges hindering effective usage of the databases in the library. It discovered that lack of awareness of the databases, low speed internet connectivity, inadequate online databases and lack of skills in searching the databases. Suggestions were also made on the way forward in combating these challenges. The study also indicated that e-resources are very useful to researchers, PubMed and Hinari are the most used databases. Furthermore, it was strongly recommended that the library should market and explore more online resources to attract more users and to do more effective research at icddr,b. Study Limitations: The present study is confined to the current status and trend of using e-resources used by the researchers of icddr,b. The study highlights on the types of web-based resources and services available in icddr,b Library and a small number of samples (213) are covered in this study. Practical implications: Many years later, the icddr,b library will receive a greater impact than present in terms of facilities and services. Other libraries in Bangladesh will also be motivated to develop Intranet site and provide library services through Intranet in respective organization. Ultimately, new system of libraries will be developed and users will be benefited using this new system. Social implications: Library community and others society of Bangladesh will be benefited in reading and using this article. Originality/value – Many papers have been written on electronic resources, but this study specifically focused on subscribed, open access and registered online resources, and it is the first time that an investigation has been made on the use of electronic resources by library users in icddr,b library. The results of the study could be useful for icddr,b Library and other medical libraries in Bangladesh in ensuring that there is a high use of web-based library facilities and services. So that other libraries in Bangladesh will be inspired and encouraged to introduce digital tool facilities and services in libraries of Bangladesh

Biomass distribution and material translocation in two herbaceous lianas in flood plain ofa regulatedriver

omass distribution and materials (total nitrogen, total phosphorous and carbohydrates) translocationintwo herbaceous lianas (Pureria montana and Sicyos angulatus) were studied in the floodplain of a regulatedriver, Tama in Central Japan over their life cycle from April 2008 to June 2009. They are very aggressive vines causing ecological imbalance bytheir resou･ce allocation strategy, a high rate of net photosynthesis; and dillmal leaf movements that maximize exposure of lower canopy leaves and reduce overheating of upper canopy leaves. Few plants can survive once smothered by them･ Plant and soil samples were collected and above- and below-ground biomass were measured kom two locations with different soil characteristics along the Tama River. Total mitrogen (TN) and total phosphorus (TP) concentration in the soil of S. angulatus were higherthan those of P･ montana･ Highbiomass of S･ angulatus was recorded kom soils withhigh nutrient contents･ P･ montana, thoughproduced higher biomass in nutrient-rich soil, can even grow well on nutrient-limited soils･ The dry and nutrient-poor habitats produced higheramount of belowground biomass in kudzu than habitats with more moismreand nutrient content. The dynamics of TNand TP in plant organs showedthe highest accumulation in leaves,followed by rootsand stems in both SpeciesI The total non-structural carbohydrates had consistent seasonal dynamics among different organs ofP. montana but not in S. angulatus.Article信州大学山地水環境教育研究センター研究報告 6: 55-68(2010)departmental bulletin pape