Effects of plant growth regulators on callus induction from Cananga odorata flower petal explant

The Cananga odorata callus was initiated from petals of the C. odorata flowers on MS medium and B5 vitamins containing 30 g/L sugar and 3 g/L agar. The medium was also supplemented with different concentrations of 1-naphtalene acetic acid (NAA), and combinations of NAA with 6-benzylaminpurine (BAP) as the plant growth regulators. It was observed that the C. odorata callus could be induced on media containing the combination of 3 mg/L NAA and 0.5 mg/L BAP. High concentration of NAA gave rise to pale, whitish and friable callus after 1 - 2 weeks of culture. The optimum pH for the cell culture was about 5.7 and incubation at 25 ± 2°C, in totally dark condition

ROOFING ASSESSMENT FOR ROOFTOP RAINWATER HARVESTING ADOPTION USING REMOTE SENSING AND GIS APPROACH

Rooftop rainwater harvesting refers to the collection and storage of water from rooftops whereby the quality of harvested rainwater depend on the types of roof and the environmental conditions. This system is capable to support the water supply in almost any place either as a sole source or by reducing stress on other sources through water savings. Remote sensing and GIS have been widely used in urban environmental analysis. Thus, this study aimed to develop the roofing layer in order to assess the potential area for rooftop rainwater harvesting adoption by integrating remote sensing and GIS approach. An urban area containing various urban roofing materials and characteristics was selected. High resolution satellite imagery acquired from WorldView-3 satellite systems with 0.3 m of spatial resolution was used in order to obtain spectral and spatial information of buildings and roofs. For quality assessment, the physical and chemical parameters of the rooftop harvested rainwater were performed according to the Standard Tests for Water and Wastewater. The potential area for rooftop rainwater harvesting adoption can be identified with the detail information of the rooftops and quality assessment in geospatial environment

Influence Of Etching Time On The Porous P-Type Gallium Nitride Using Alternating Current Photo-Assisted Electrochemical Etching Technique

The Theoretical And Experimental Study Of Porous P-Type Gallium Nitride (Gan) Is Discussed In This Work. Porous P-Type Gan Was Adequately Fabricated Using Alternating Current Photo-Assisted Electrochemical Etching Technique With Various Etching Times (10, 20, 30, And 60 Minutes) In Mixed Hydrofluoric Acid And Ethanol Electrolyte Solutions (1:4 Volume Ratios) Under Ultraviolet Illuminations. The Evolution Of Morphology Of Non-Porous And Porous P-Type Gan As A Function Of Etching Time Was Imaged Using Field Emission Scanning Electron Microscopy Measurement. Surface Analysis Revealed A Sporadic Pore Size With Circular Shape Was Found In Porous P-Type Gan While Smooth And No Pores Was Observed In Non-Porous P-Type Gan Sample. Etching For A Brief Time Frame Resulted In Small Pores, And Etching For Longer Times Resulted In Enormous Pores. However, Prolonged Etching Times Of 60 Minutes Would Prompt Breakdown Of Porous Layer. The Average Pore Diameter And Porosity Of The Investigated Samples Were Estimated From The Imagej Software. Subsequent Effort By Investigating The Structural Characteristics Of Non-Porous And Porous Samples By Variety Of Methods, Including High Resolution X-Ray Diffraction And Atomic Force Microscopy. A Significant Increase In The Surface Roughness Was Observed With An Increase In The Etching Time. The Discoveries Found That The Influence Of Etching Duration Has Indicated Noteworthy Impacts Towards Morphological And Structural Properties Of The Porous P-Type Gan, As Supportively Revealed Through Pore Size, Porosity, And Surface Roughness

Influence Of Etching Time On The Porous P-Type Gallium Nitride Using Alternating Current Photo-Assisted Electrochemical Etching Technique

The theoretical and experimental study of porous p-type gallium nitride (GaN) is discussed in this work. Porous p-type GaN was adequately fabricated using alternating current photo-assisted electrochemical etching technique with various etching times (10, 20, 30, and 60 minutes) in mixed hydrofluoric acid and ethanol electrolyte solutions (1:4 volume ratios) under ultraviolet illuminations. The evolution of morphology of non-porous and porous p-type GaN as a function of etching time was imaged using field emission scanning electron microscopy measurement. Surface analysis revealed a sporadic pore size with circular shape was found in porous p-type GaN while smooth and no pores was observed in non-porous p-type GaN sample. Etching for a brief time frame resulted in small pores, and etching for longer times resulted in enormous pores. However, prolonged etching times of 60 minutes would prompt breakdown of porous layer. The average pore diameter and porosity of the investigated samples were estimated from the ImageJ software. Subsequent effort by investigating the structural characteristics of non-porous and porous samples by variety of methods, including high resolution x-ray diffraction and atomic force microscopy. A significant increase in the surface roughness was observed with an increase in the etching time. The discoveries found that the influence of etching duration has indicated noteworthy impacts towards morphological and structural properties of the porous p-type GaN, as supportively revealed through pore size, porosity, and surface roughnes

Enhancing Performance of Porous Si-Doped GaN based MSM Photodetector Using AC Technique

In this work, we report the formation of porous Si-doped GaN films under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical etching (ACPEC) conditions. The formation of porous Si-doped GaN by the novel ACPEC is performed in the same electrolyte concentration (4% KOH) used in common de constant current electrochemical etching process. Ultra-violet (UV) illumination is used to assist in the generation of electron-hole pairs, where etching proceeds through the oxidation and consequently, dissolution of the semiconductor surface. The ac formed porous Si-doped GaN with excellent structural and optical properties. According to the FESEM micrographs, the GaN thin films exhibit a homogeneous nanoporous structures with spatial nano-flakes arrangement. The porous layer exhibited a substantial photoluminescence (PL) intensity enhancement with red-shifted band-edge PL peaks associated with the relaxation of compressive stress. The shift of E2(high) to the lower frequency in Raman spectra of the porous GaN films further confirms such a stress relaxation. Electrical characterizations of the MSM photodiodes were carried out by using current-voltage (1-V) measurements indicated that the devices were highly sensitive to ambient light

Comparative Studies Between Porous Silicon And Porous P-Type Gallium Nitride Prepared Using Alternating Current Photo-Assisted Electrochemical Etching Technique

Porous n-type Si and porous p-type GaN nanostructures were fabricated using alternating current photo-assisted electrochemical (ACPEC) etching in 1:4 volume ratio of hydrofluoric acid (HF) and ethanol (C2H5OH) for a duration of 30 minutes. The aim of this work is to study pore formation on the Si and p-GaN substrates in the aspects of morphological and structural changes. The morphological and structural properties of porous Si and porous p-type GaN samples have been studied using field emission scanning electron microscopy (FESEM) measurement, energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and high-resolution X-ray diffraction (HR-XRD) in comparison to the respective as-grown sample. FESEM analysis revealed that uniform pore size with triangular-like shape was formed in porous Si sample while circular-like shape pores were formed in the porous p-type GaN sample. AFM measurement revealed that the root-meansquare surface roughness of porous Si and porous p-GaN was 6.15 nm and 5.90 nm, respectively. Detailed investigation will be presented in this work to show that ACPEC etching technique is a viable technique to produce porous nanostructures in different substrates

Enhancing Performance Of Porous Si-Doped GaN Based Msm Photodetector Using 50 Hz Acpec

In this work, we report the formation of porous Si-doped GaN films under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical etching (ACPEC) conditions. The formation of porous Si-doped GaN by the novel ACPEC is performed in the same electrolyte concentration (4% KOH) used in common dc constant current electrochemical etching process. Ultra-violet (UV) illumination is used to assist in the generation of electron-hole pairs, where etching proceeds through the oxidation and consequently, dissolution of the semiconductor surface. The ac formed porous Si-doped GaN with excellent structural and optical properties. According to the FESEM micrographs, the GaN thin films exhibit a homogeneous nanoporous structures with spatial nano-flakes arrangement. The porous layer exhibited a substantial photoluminescence (PL) intensity enhancement with red-shifted band-edge PL peaks associated with the relaxation of compressive stress. The shift of E2(high) to the lower frequency in Raman spectra of the porous GaN films further confirms such a stress relaxation. Electrical characterizations of the MSM photodiodes were carried out by using current-voltage (I-V) measurements indicated that the devices were highly sensitive to ambient light

Production of hydrolytic enzymes in rice (Oryza sativa L.) roots inoculated with N2-fixing bacteria

An experiment was conducted to determine the production of hydrolytic enzymes endoglucanase (EG) and endopolymethylgalacturonase (EPMG) in rice (Oryza sativa L.) roots inoculated with N2-Fixing bacteria. Screening for hydrolytic enzymes by N2-Fixing bacteria, using the plate method showed that nine out of 12 bacterial strains were positive for carboxymethylcellulose (CMC) and pectin reactions. Three of the isolates, Sb34, Sb41 and Sb42 were inoculated to MR219 rice seedling. The bacterial population and the production of hydrolytic enzymes were monitored for 45 days of plant growth. The scanning (SEM) and transmission electron microscopy (TEM) were used to observe bacterial colonization on plant roots. In general, the populations of inoculated diazotrophs were higher in the rhizosphere than the endosphere. There were significant effects of different diazotrophs inoculations on the rice rhizosphere and endosphere populations. Plants inoculated with diazotrophs showed significantly higher specific enzyme activities and soluble proteins compared to the non-inoculated control. SEM and TEM observations revealed the abilities of the diazotrophs to colonize the surfaces and interior of the roots. Inoculation significantly increased root growth of rice with substantial increase in root length, volume and surface area in the inoculated plants