Potential of Moringa Oleifera Seed as a Natural Adsorbent for Wastewater Treatment

The present study deals with the appropriateness of the coagulation process using natural coagulant Moringa oleifera seed. Natural coagulants are useful for the treatment of wastewater because of its sustainability, cost-effectiveness, non-toxicity and lesser quantity of sludge formation. M. oleifera seed having a chemical composition of polypeptides having 6 amino acids like arginine acid, methionine acid, glutamic acid, phenylalanine, threonine, and histidine. M. oleifera is also known as a cationic polyelectrolyte and having molecular weight 6,000 to16,000 Dalton. The main objective of research work is the application of the M. oleifera seed as a natural adsorbent to treat synthetic dairy wastewater. The effects of pH, agitation time, the dose of sorbent and efficacy of M. oleifera seeds kernel for turbidity removal was assessed. M. oleifera seed eliminates turbidity 95 % and colour 94 % using 0.22 gm pod powder, and 0.2 L of 1.0 g/L synthetic dairy wastewater. Naturally dried M. oleifera seeds remove turbidity 95 %, sundried seeds remove turbidity 52 % and oven-dried seeds 45 %. As naturally dried M. oleifera pod having more surface area for adsorption and inter-particulate bridging which extract the extra active ingredients. pH range between 5 and 8 is more suitable to degrade the turbidity and colour. It is concluded that in the presence of an aqueous soluble cationic coagulant protein has great potential to remove the turbidity and colour of wastewater. HIGHLIGHTS oleifera seed having a chemical composition of polypeptides having 6 amino acids like arginine acid, methionine acid, glutamic acid, phenylalanine, threonine, and histidine oleifera seeds consist of crude fiber, lignin, hemicellulose, and cellulose. It also contains amino functional groups (R-NH3), carboxyl group (C=O), and fiber carbonaceous. The functional group present in M. oleifera seeds is dissociated during the adsorption process at various pH oleifera has good property of coagulation-flocculation (C-F) The effectiveness of naturally dried seed kernel is more effective than other seed kernels GRAPHICAL ABSTRACT

Mineralogical and Geochemical Characteristics of Carbonate Rocks for Lime Industry in Ban Pong, Chiang Mai Province, Northern Thailand

One of the oldest lime manufactures in Chiang Mai Province is located in a hillside village, Ban Pong, Hang Dong District, the western part of Chiang Mai City. Villagers still have conserved traditional production methods using wood-fired kilns and the primary material selection, an Ordovician marble. There are 2 massive amounts of carbonate rocks distributed in Chiang Mai Province; Permian limestone and Ordovician marble. However, the Ordovician carbonate rocks in Ban Pong were selected to produce high-quality lime by their primitive method (man-made) for a long time. Petrographical studies suggest that the Ordovician rock samples show a granoblastic texture with a slightly foliation represents by mica flakes. They are made up mainly of calcite, with very small amounts of quartz, muscovite, talc, and opaque minerals that can be identified as marble. The mineral compositions are according to the value of CaO, SiO2, Al2O3, K2O, and Fe2O3 in whole-rock analysis by XRF. The geochemical data suggest that marble in the Ban Pong area has a high CaO ratio and contains small amounts of muscovite, quartz, talc, and opaque minerals that may reduce the decomposition temperature during the calcination process. The Ordovician marble in Ban Pong is an appropriate raw material for traditional lime manufacture to saving energy in the production system. HIGHLIGHTS Limestone has been a geologic material in the lime industry from the past to the presence of human society Villagers in Ban Pong (Chiang Mai Province, Thailand) selected the western Ordovician limestone mountains to produce lime by a primitive process instead of the eastern Permian limestone mountains The mineral- and chemical compositions of the Ordovician limestones were intensively analyzed to characterize the suitable raw materials for a primitive lime kiln The mineral composition indicated that the Ordovician limestone in this area is metamorphosed into an impure fine-grained marble GRAPHICAL ABSTRACT

On Degree Based Topological Indices of TiO2 Crystal via M-Polynomial

Topological indices (TI) (descriptors) of a molecular graph are very much useful to study various physiochemical properties. It is also used to develop the quantitative structure-activity relationship (QSAR), quantitative structure-property relationship (QSPR) of the corresponding chemical compound. Various techniques have been developed to calculate the TI of a graph. Recently a technique of calculating degree-based TI from M-polynomial has been introduced. We have evaluated various topological descriptors for 3-dimensional TiO2 crystals using M-polynomial. These descriptors are constructed such that it contains 3 variables (m, n and t) each corresponding to a particular direction. These 3 variables facilitate us to deeply understand the growth of TiO2 in 1 dimension (1D), 2 dimensions (2D), and 3 dimensions (3D) respectively. HIGHLIGHTS Calculated degree based Topological indices of a 3D crystal from M-polynomial A relation among various Topological indices is established geometrically Variations of Topological Indices along three dimensions (directions) are shown geometrically Harmonic index approximates the degree variation of oxygen atom

Electronic Load Controller based on Dimmer Circuit and Stepper Motor for 5 kW Micro-Hydro Power Plant

This paper presents the results of research on a new schematic generator load controller simulation, namely an electronic load controller based on a dimmer circuit and a stepper motor for a small-scale 5 kW micro-hydro. The load controller is built from a dimmer circuit and a stepper motor with program control using Matlab software, and the PPI 8255 interface device. Using a dimmer circuit built from diac, triac, a variable resistor (pot), and capacitor components. As well as using a 28BYJ-48 stepper motor. Simulation is made to determine the performance of the load controller in controlling the distribution of power to the ballast load when the generator supplies power to consumers less than the full load of the generator. By using the simulation data of 45 variations of the consumer load sample, the result is that there are only 4 samples where the load controller is not working well. For the 4 samples, the generator was loaded beyond its full load tolerance limit (full load tolerance of 5kW ± 5 %). Overall, based on the simulation results, it can be said that the generator load controllers tested in this study have good performance. HIGHLIGHTS Methods and power electronic configurations used in electronic load controllers for micro-hydropower plants from 1980 until now. In the future, the use of low-power micro hydro and pico hydro power plants is also in great demand, especially for rural areas The utilization of micro-hydro in Indonesia, especially low-power micro-hydro, has been utilized by the community in Bulukumba Regency, South Sulawesi Province. A 5 kW generator has been operated in Katimbang Village, Borong Rappoa District, Kindang Regency, Bulukumba Regency, South Sulawesi Province to distribute electrical energy to 15 households This research proposes a new electronic load control scheme for a simple and inexpensive 5 kW micro-hydro power plant, namely a dimmer circuit and stepper motor-based generator load controller. With the consideration that the main components that make up this controller are not expensive GRAPHICAL ABSTRACT

Investigation of Screen Time Inclination and the Accompanying Visual and Musculoskeletal Discomfort in Young Smartphone Users

The purpose of this study is to investigate the screen time inclination and its accompanying visual and musculoskeletal discomfort in young smartphone users. Thirty-one smartphone users aged between 20 - 30 years old were recruited through convenient sampling. The screen time patterns were recorded daily for a week and documented using Action Dash on Google Play Store according to the times of the day (morning, afternoon evening and night). Accompanying visual and musculoskeletal symptoms were examined through a self-reporting questionnaire survey. The questions used in the questionnaire were adapted and modified from the Asthenopia Questionnaire and Nordic Musculoskeletal Questionnaire. Results showed that young smartphone users spent approximately 30 % of their time on screen and were relatively similar for different times of the day. Daily screen time was approximately 7.36 ± 1.74 h. Most users engaged in WhatsApp (74 %), followed by YouTube (68 %), Instagram (65 %) and Twitter (39 %). Tired eyes were reported by all smartphone users. A positive correlation was only found between weekly screen time and eye strain (p < 0.05). All musculoskeletal symptoms were self-reported by young smartphone users in our study but anatomical locations varied in percentages. Neck pain was the most significant musculoskeletal symptom associated with screen time (OR = 4.80, 95 % CI: 0.95 - 24.14, p < 0.05). Every smartphone user reported at least 1 type of visual symptom. All smartphone users reported tired eyes. In conclusion, our results showed that smartphone users spent one third of their time daily on-screen and mostly on social media. Tired eyes and neck pain were the most common accompanying symptoms. Visuo-skeletal symptoms are common among young and healthy smartphone users. Our findings advocate that future strategic plans to address digital related health problems from the perspective of health education, promotion and protection should be inclusive of youth. HIGHLIGHTS Excessive screen time is a public health concern Adverse health implications have been linked to excessive electronic usage Smartphone users spend one-third of their time daily on-screen and mostly on social media Visuo-skeletal symptoms are common among young and healthy smartphone users Tired eyes and neck pain are the most common accompanying symptoms GRAPHICAL ABSTRACT

Effect of Nutrients on Diatom Growth: A Review

Diatoms are one of the unicellular algae with a rare presence of unaltered, durable, transparent and species-specific silica frustules that persist even after cell death in the deposits of water bodies. Diatom has high capacity for absorption of metals for maintaining the water quality and high rate of multiplication. These characters promoted the use of this microbial biomass for effluent detoxification. These diatoms can also solve metal toxicity problems in aquatic ecosystems in the water polluted environment. In the present review, the focus is on several nutrients (nitrogen, phosphorus, iron and silica) that are essential for the growth of diatoms at very low concentrations, but most of them are toxic at high concentrations. It also shows the relationship between heavy metal stress and lipid body induction which may be a valuable indicator for the evaluation of heavy metal contamination of fluvial ecosystems. HIGHLIGHTS Diatoms are eukaryotic, unicellular, photosynthetic, silica-containing microscopic algae with distinct geometric forms Diatoms are used for biomonitoring purposes for taxonomic and morphological properties of ecosystems, community and human disturbances Diatoms are also the primary producer of oil in the world responsible for fixing 25 % of CO2 and 30 % of crude oil diatoms Many diatoms are appropriate for lipid development up to 70 % of their body volume and are investigated for biofuel as a hotspot GRAPHICAL ABSTRACT

A Decision-Making Model of Technological-Focused Government Agency Selection of Technological Start-Up Businesses

In developing countries, the government has played an important role in supporting startup businesses in various aspects, primarily through tech-focused government agencies. With a limited budget, the government agencies are critical to select plenty of tech startups for funding, leaving only promising tech startups. Consequently, government agencies inevitably face decision-making problems under uncertain circumstances, like private equity investment situations. Reviewing the relevant decision-making frameworks has identified that a classical multiple criteria decision-making (MCDM) approach is currently used, assuming decision-makers acquire complete information that is not realistic. Moreover, both qualitative and quantitative criteria used in evaluating startup businesses cannot represent the uncertainty which is the fundamental nature of the decision-making circumstance. Thus, this article presents a decision-making framework of tech-focused government agencies for selecting startup businesses based on a fuzzy MCDM of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Besides, it identifies selection criteria with mixed research methodologies and determines weights of importance criteria by the Delphi method. Finally, the proposed framework results are fairness, transparency, and eliminating bias in decision-making, including more efficiency when the framework’s ranking orders significantly correspond with actual performances. HIGHLIGHTS Criteria for selecting start-up businesses in technological-focused government agencies A decision-making framework of tech-focused government agencies for selecting startup businesses based on a fuzzy MCDM of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) The performance of the decision-making framework in selecting startup businesses to acquire high potential tech startups to drive the national economy GRAPHICAL ABSTRACT

Gold Coated VO2 Nanogratings Based Plasmonic Switches

This paper presents 2 dimensional (2D) and 1 dimensional (1D) gold (Au) coated VO2 (Vanadium Dioxide) nanogratings based tunable plasmonic switch. VO2 is a phase changing material and hence exhibits phase transition from semiconductor to metallic phase approximately at 67 ºC or 340 K (critical temperature) which can be achieved by exposure to IR radiation, application of voltage, heating, etc. and there is a huge contrast between optical properties of its metallic and insulating phases and hence that can be utilized to implement VO2 based optical switches. These VO2 based gratings couple the incident optical radiation to plasmonic waveguide modes which in turn leads to high electromagnetic field enhancement in the gaps between the nanogratings. The proposed Au coated VO2 nanogratings can be fabricated by using current state of art fabrication techniques and provides switchability of the order of femtoseconds. Hence the optical switching explained in our paper can be used fast switching applications. For an optimum switch our aim is to maximize its differential reflectance spectra between the 2 states of VO2, i.e., metallic and semiconductor phases. Rigorous Coupled Wave Analysis (RCWA) reveals that wavelengths for maximum differential reflectance can be optimized over a large spectral regime by varying various parameters of nanogratings for example groove height (h), width (w), gap (g) between the gratings, and thickness (t) of Au coating over VO2 by simulation using RCWA for maximum differential reflectance between VO2 metal and semiconductor phase, i.e., the switching wavelengths can be tuned by varying grating parameters and thus we can have optimum optical switch.

Synthesis, Characterization and Photocatalytic Performance of Poly-3-Thenoic Acid/Cu-TiO2 Nanohybrid for Efficient Visible Light Assisted Degradation of Bismarck Brown R

The present work reported on the synthesis and characterization of Poly-3-Thenoic acid/Cu-TiO2 nanohybrid (PCuT) for the photocatalytic degradation of organic azo dye pollutant from wastewater. The as-synthesized nanohybrid by an in-situ modified sol-gel method including chemical oxidative polymerization was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-vis.DRS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET) surface area analysis. The characterization results revealed the formation of small aggregates of polymer contained high crystalline anatase TiO2 nanoparticles (XRD) with narrowed bandgap energy (UV-vis.DRS), decreased particle size (TEM) with smooth surface morphology (SEM) and large surface area (BET). All the constituent elements of the polymer and Cu-TiO2 were found in the PCuT nanohybrid material (EDX) and their chemical interaction studied by FT-IR confirmed the stability of the nanohybrid. The photocatalytic activity of the nanohybrid was tested by the degradation of Bismarck Brown R dye under visible light irradiation. To enhance the photocatalytic efficiency, effects of various catalyst/dye reaction parameters such as polymer content, solution pH, catalyst dosage, and initial dye concentration were studied and optimized. HIGHLIGHTS Poly-3-Thenoic acid/Cu-TiO2 nanohybrid material was successfully synthesized by in situ modified sol-gel process Poly-3-Thenoic acid has enhanced the visible light absorption capacity of anatase TiO2 in nanohybrids Electron-hole recombination in TiO2 was effectively inhibited by Cu doping Bismark Brown R, an organic pollutant was successfully degraded in 75 min of visible light irradiation GRAPHICAL ABSTRACT

Comparison of Ultimate Capacities of RC Chimney Sections under Wind Loading

Diffusion of gaseous and particulate pollutants from tall stacks has formed an important element in the control of air pollution since the industrial revolution began. These tall reinforced concrete chimneys are considered to be cantilever columns subjected to axial load resulted from the self-weight of the shell, linings and other accessories and bending moments which are resulted from the lateral loads like wind forces and earthquake forces. The recently published IS: 4998 – 2015 adopted a limit state design concept which requires well defined stress-strain relationship for concrete and steel. It has been seen that there are many disparities lies between the stress-strain relationships of constituent materials adopted by IS: 4998 – 2015 and other design standards. This paper discusses various methods pertaining to the estimation of the ultimate strength of thin-walled hollow circular sections of reinforced concrete chimneys, subjected to wind loading. A comparative study of various methods based on the prevalent codes reveals considerable disparity in the predicted ultimate strength values. These differences have been critically analyzed and results are discussed in this paper in terms of ultimate strength along with the contribution of concrete and steel, ultimate curvature and depth of neutral axis. For the comparison of above-mentioned parameters, design recommendations of IS 4998 – 2015, CICIND 2011, ACI 307 – 08 are used. HIGHLIGHTS The recently published IS: 4998 – 2015 adopted a limit state design concept which requires well defined stress-strain relationship for concrete and steel which differs in terms of strain and stress limits when compared with other well established RC chimney design codes Various methods pertaining to the estimation of the ultimate strength of thin-walled hollow circular sections of reinforced concrete chimneys, subjected to wind loading are discussed using a comparative study with different parameters of RC chimney For the comparison of above-mentioned parameters, design recommendations of IS 4998 – 2015, CICIND 2011, ACI 307 – 08 are used Stress-strain relationship of concrete and steel also discussed with the bases of the same is also discussed in detail for each of the above codes GRAPHICAL ABSTRACT