The new pendent bisphenol containing flourene unit, 1,1-bis-(4-hydroxyphenyl)-1-(9H-fluoren-2-yl)ethane (BHPFE) are synthesized from commercially available 2-acetylfluorene and phenol and then ...utilized for the synthesis of three new kinds of polyarylates by phase-transfer catalyzed interfacial polycondensation technique with two different benzenedicarbonyl chlorides (isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC)) and its mixture of 50:50 mol%. The synthesized BHPFE and polyarylates are well-characterized using FTIR,
1
H-NMR,
13
C-NMR, and GPC measurements. Results of these new polyarylates are compared with aromatic polyesters derived from Bisphenol-A with TPC as well as IPC. Inherent viscosities and number average molecular weights (Mn) of polyarylates are found in the range of 0.11–0.71 dl/g and 59,516–79,371 g/mol, respectively. Compared with the polyarylates synthesized from Bisphenol-A, the polyarylates synthesized from BHPFE monomers exhibited high solubility in various organic solvents like dichloromethane, tetrahydrofuran, chloroform, pyridine and N, N-dimethylformamide and could be easily solution-cast into transparent films. The WXRD study indicated that new polyarylates are amorphous in nature. Polyarylates showed the glass transition temperature (T
g
) inbetween 123–151 °C and 10% weight loss (T
10
) ranging from 399°–447 °C under nitrogen atmosphere indicating their thermal stability. Polyarylates having tensile strength of 3.35 to 5.36 MPa with optical transparency cutoff in the wavelength of 309–326 nm range.
Abstract
This article describes the controlling of robot arm using different operations with choice. It is a programmable arm to hold and place the objects. Also it can change the position of the ...objects. The addition features are added to robotic arm using a reprogrammable FPGA mechanism. The robotic arm parts are jointed to give flexible move and rotate movements. We have used spartan3 FPGA to implement and test the robot arm conditions. We have used digital controlling inputs to control the robot arm directions.
Our earlier studies have evaluated the effect of meltblowing process parameters on fiber diameter and orientation distribution. This paper deals with parametric studies evaluating the effect of ...polymer throughput, attenuating air pressure, take-up speed of the web, fiber stream approach angle, and die-to-collector distance (DCD) on pore sizes and their distribution in meltblown nonwoven webs. Pore sizes and their cumulative frequency are determined by an automated perm porometer. Under the conditions explored, the average pore size of meltblown fabrics decreases significantly when the attenuating air pressure increases. Pore size decreases significantly when the take-up speed of the web increases. As expected, an increase in the polymer throughput increases the average pore size. Increasing the DCD initially decreases, then increases pore size. confirming the existence of different "zones" in the space between the die and collector. An increase in the fiber stream approach angle initially decreases, then significantly increases pore size in the web.
An instrument is developed to detect and analyze the acoustic emission generated during tensile fracture of each of the single fibers in a beard containing 100-150 fibers. The acoustic pulse height ...and width are recorded coincident with the tensile breaking load and breaking elongation. Ten different varieties of cotton fibers are tested on the instru ment and on standard HVI equipment. There is a nonlinear relationship between the acoustic pulse height and breaking load, as well as between the acoustic pulse energy density and the work of rupture of the fibers. The acoustic pulse energy density is a new datum obtained separately from HVI data, and so it can be used as an additional parameter for classifying cotton fibers.
Meltblown nonwovens have been produced as 2D web structures for a variety of end uses. Investigation into the development of 3D structures has resulted in a parametric evaluation of the process and ...its effects on the structural properties of the webs (fiber diameter, fiber orientation, and pore size distributions). The interrelationships between these structural parameters have been explored and a statistical model developed. SAS was used to develop the correlations between the structural parameters of the web. The pore diameter is found to be directly proportional to the fiber diameter and inversely related to the web anisotropy parameter. The relationship that was established for the 2D webs correlates to the relationship developed for the 3D web structures.
Meltblown nonwovens have been produced as 2D web structures for a variety of end uses. Investigation into the development of 3D structures, has led to the integration of meltblown and robotic ...technology to form the Robotic Fiber Assembly and Control System. The effect of curvature of the collecting surface on the structural properties of the webs such as the diameter and orientation distributions of the fibers and the pore size distribution on the webs has been investigated. The relative frequency of fibers oriented in the machine direction increased significantly when the curvature of the collecting surface increased, while the average pore size of the web decreases due to the increased orientation of fibers in the direction of collection.
We investigated the effect of seed mass on emergence, seedling survival and growth ofPterocarpus marsupium Roxb., a medium to large, commercially valuable and deciduous tree species. Among the three ...size classes viz. small （10-12 mm）, medium （13-15 mm） and large （16-17 mm）, the maximum proportion, of seed by number （54.12%） and dry weight （51.87%） was recorded, in the medium size seed class. Seed length and seed width were greatest in the large seed class （16.50 mm, 7.33 mm） followed by medium （13.50 mm, 5.60 mm） and small （11.37 ram, 3.66 mm）. Similarly, hundred seed weight （100 sw） varied from a maximum of 12.92 g in the large seed class to intermediate 10.95 g in the medium seed class and minimum of 7.02 g in the small seed class. The large seed size showed maximum emergence and shoot length over the medium and small seed class. After six months of growth, significant variations due to seed size were also observed for the growth and dry weight of P. marsupium seedlings. Seedling vigour, expressed in terms of height, collar diameter, number of leaves and dry biomass, was sig- nificantly affected by seed class. Seedlings that emerged from large seeds showed better growth and produced heavier seedlings as compared to medium and small seeds.
Ethylene signal transduction in plants is conducted by the two-component system (TCS) which consists of histidine kinase (HK), histidine phosphotransferase (HPT) and response regulators (RRs). This ...system plays an important role in signal transduction during various cellular processes, including fruit ripening and response to multiple environmental cues. Though members of TCS have been identified in a few plants, no detailed analysis has been carried out in banana.
Through genome-wide analysis, we identified a total of 80 (25 HK, 10 HPT and 45 RR) and 72 (25 HK, 5 HPT and 42 RR) TCS genes in Musa acuminata and Musa balbisiana respectively. The analysis of identified genes revealed that most of the genes are highly conserved however; there are subtle divergences among various members. Comparative expression analysis revealed an involvement of a set of TCS members during banana fruit ripening. Co-expression network analysis identified a working TCS module with direct interactions of HK-HPT and RR members. The molecular dynamics analysis of TCS module showed a significant change in structural trajectories of TCS proteins in the presence of ethylene. Analysis suggests possible interactions between the HK-HPTs and RRs as well as other members leading to banana fruit ripening.
In this study, we identified and compared the members of TCS gene family in two banana species and showed their diversity, within groups on the basis of whole-genome duplication events. Our analysis showed that during banana fruit ripening TCS module plays a crucial role. We also demonstrated a possible interaction mechanism of TCS proteins in the presence and absence of ethylene by molecular dynamics simulations. These findings will help in understanding the functional mechanism of TCS proteins in plants in different conditions.
Metal–organic polyhedra (MOP) are a promising class of crystalline porous materials with multifarious potential applications. Although MOPs and metal–organic frameworks (MOFs) have similar potential ...in terms of their intrinsic porosities and physicochemical properties, the exploitation of carboxylate MOPs is still rudimentary because of the lack of systematic development addressing their chemical stability. Herein we describe the fabrication of chemically robust carboxylate MOPs via outer‐surface functionalization as an a priori methodology, to stabilize those MOPs system where metal–ligand bond is not so strong. Fine‐tuning of hydrophobic shielding is key to attaining chemical inertness with retention of the framework integrity over a wide range of pH values, in strong acidic conditions, and in oxidizing and reducing media. These results are further corroborated by molecular modelling studies. Owing to the unprecedented transition from instability to a chemically ultra‐stable regime using a rapid ambient‐temperature gram‐scale synthesis (within seconds), a prototype strategy towards chemically stable MOPs is reported.
Systematic stability: A correlation between the hydrophobicity and chemical stability of metal–organic polyhedra (MOP) was uncovered. Enhancement of the chemical stability is a consequence of the incremental hydrophobicity of the surfaces for systems where the internal core of each cage is similar. Structural characterizations and simulation data are presented.
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