Economic Valuation of River Conservation towards International Tourists’ Preferences and Willingness to Pay for Ecofriendly Services of Hotel Industry: A Case Study of Namxong River in Vangvieng District, Laos

Using choice experiment, the objective of this study is to estimate international tourists’ preferences and willingness to pay for ecofriendly services which related to river and natural environment conservation of hotel industry in Vangvieng, a popular tourist town in Lao PDR. We used the mixed logit to take into account of preference heterogeneity by allowing coefficients to be normally distributed and assumed to vary among individuals. The result shows that all ecofriendly practices offered in this study are significantly preferred by tourists. Income, age, and education did not have significant effect on the probability of choosing ecologically friendly practices of hotel and attributes to support the ecotourism of the area;however, this study provides important information that female tourists are more receptive to a new alternative. These findings do not only support the provision of good and green services in Vangvieng Town, but will also be useful for policy maker to enhance the sustainability of ecotourism in Laos.

Synthesis of Ecofriendly Self-crosslinking Adhesive and Its Application in Pigment Printing

Glycidyl acrylate was synthesized successfully utilizing phase - transfer catalyst and was applied to emulsion polymerization of acrylates as the crosslinking agent. Combined with other two kinds of crosslinking agents, a new type of ecofriendly self - crosslinking adhesive was prepared . Factors affecting the preparation such as reaction temperature, initiator, eniulsifiers, reaction time and so on were studied comprehensively. Properties in relation to pigment printing of the prepared adhesives were also tested and compared with two kinds of commercial adhesives that have been widely applied in printing industry.

Ecofriendly Disease Management of Lentil (<i>Lens culinaris</i>) Seedlings

To determine the effect of Biofertilizer and Integrated Pest Management (IPM) biopesticide for controlling foot and root rot diseases of lentil it is very important for conducting experiment in the field. It was marked that both Biofertilizer and IPM Biopesticide found significantly lower disease incidence of Bangladesh Institute of Nuclear Agriculture (BINA) released popular lentil variety Binamasur-1 and Binamasur-2 seedlings compared with the control treatment. Soil treatment with Biofertilizer as Bangladesh Agricultural Research Institute (BARI) released Bari-Biofertilizer performed the lowest disease incidence of lentil variety Binamasur-1 and Binamasur-2 at 20 days after sowing (DAS) showed a reduction of disease incidence up to 68.80% and 71.70% over the control. While after 28 DAS, it was found up to 91.27% and 91.34% reduction of disease incidence over control. Furthermore, after 35 DAS, it exhibited up to 69.37% and 69.28% reduction of disease incidence over control. Bari-Biofertilizer significantly increased the fresh weight and the number of nodules per plant.

Ecofriendly leaching agents for copper extraction-An overview of amino and organic acid applications

The green transition’s push for electrification has substantially increased the demand for copper,making it a critical raw material.This extravagant demand has made it profitable to extract copper from low-grade sulfide ores,which contain less than 0.3wt%copper.However,processing such low-grade ores requires extensive amounts of chemicals,raising environmental concerns.Thus,several investigations have been conducted on non-traditional lixiviants for copper extraction.Surprisingly,few studies have comprehensively reviewed this area to provide a comprehensive understanding and highlight gaps.This review analyzes investigations that have worked on the leaching process of copper into solutions using environmentally friendly reagents,particularly organic acids and amino acids,and compare them to conventional inorganic acids and examines recent advancements in ecofriendly leaching agents,specifically their application in copper leaching.The primary objective is to highlight the significance of these green reagents in mobilizing copper from solid to solution phases.It was highlighted that factors,such as mineralogy,mechanical activation,impurities,particle size,temperature,and initial concentration of the leaching agent,influence the leaching efficiency of organic and amino acids from primary and secondary copper resources.These variables interact in more complex ways than those encountered with conventional leaching methods.Research in this area has shown promising results,both in terms of extraction efficiency and reduced environmental impact,making it an exciting and essential area for further exploration and development.This shift towards using nonconventional lixiviants represents a significant step forward in the quest for more sustainable and environmentally responsible mining practices and recycling processes.

Seed Extract of Psidium guajava as Ecofriendly Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Medium

The anticorrosion characteristics of the seeds of Psidium guajava （P. guajava） fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of ad- sorption of the inhibitor on the metal surface （Q）, change in entropy （ΔS）, change in flee energy of the reaction （ΔG）, corrosion rate （CR） and energy of activation for corrosion reaction of carbon steel （E） were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investi- gated using Fourier transform infrared （FT-IR） spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy （SEM） micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.

2-Aminopyridine functionalized cellulose based Pd nanoparticles： An efficient and ecofriendly catalyst for the Suzuki cross-coupling reaction

A palladium catalyst supported on 2-amino- pyridine functionalized cellulose was synthesized and fully characterized by inductively coupled plasma atomic emission spectroscopy, transmission electron microscope, Fourier transform infrared spectroscopy, thermogravi- metric analysis and X-ray photoelectron spectrometry. This catalyst can be applied in the Suzuki cross-coupling reaction of aryl halides with arylboronic acids in 50% ethanol to afford biaryls in good yields, and easily recycled by simple filtration after reaction without the loss of metal Pd.

Study of tribological properties of ecofriendly lubricant additives derived from leaf-surface waxes

Three kinds of leaf-surface waxes are extracted from the leaves of Euonymus japonicas(EJ), Sabina chinensis(SC) and Sabina procumbens(SP) to be tested for their tribological properties. Lubricating oils containing these 3 waxes respectively were analyzed via gas chromatography-mass spectrometer(GC-MS) for their chemical constituents and tested with friction and wear testing machine and time of flight secondary ion mass spectrometry(TOF-SIMS) for the tribological mechanism. It was found that all the tested cuticular wax can reduce the coefficient of friction, and the waxes of SC and EJ can reduce the wear width. The contents of acid and esters in the wax can improve the friction reducing property by forming tribochemical films on the metal, but result in the increase of wear due to corrosion. The increase of ions containing C, H, O and the decline of aluminum positive ions on the worn surface,demonstrate that the tribofilms derived from long chain compounds play a role of protecting the metal surfaces.

Screening of some indigenous herbal dyes for use in plant histological staining

The efficacies of some indigenous herbal dyes for use in staining plant materials were examined to obtain non-toxic, eco-friendly and cheap stains for use in plant histology. Dye extracts from Bixa orellana, Curcuma domestica, Lonchocarpus cyanescens and Pterocarpus osun were used to stain wood sections using the existing standard staining procedures with little modification. All the extracts had affinity for the fibre and vessel elements except the extract from L. cyanescens. The extracts from C. domestica and B. orellana had higher selectivity than those ofP. osun for fibre. From the results of the absorbance curves, each of the dye extracts from all speciese had minimum of two peaks, indicating that they had two or more colour imparting chromophores except dye extract from C. domestica. All the dye extracts were acidic with pH range of 3.77 to 6.77. Therefore, this study shows that dye extracts from B. orellana, C. domestica and P. osun could be solitarily or in combination with artificial dyes for plant histological staining.

Seed Priming and Foliar Supplementation withβ-aminobutyric Acid Alleviates Drought Stress through Mitigation of Oxidative Stress and Enhancement of Antioxidant Defense in Linseed(Linum usitatissimum L.)

Drought is one of the critical limitations to agricultural soils and crop plants.Scarcity of water is increasing due to climate change that lead to increasing threats to global food security.Therefore,ecofriendly and cost effective strategies are highly desirable for mitigating drought stress along with sustainable and smart agricultural production.The aim of the study was to mitigate DS using seed priming and exogenous supplementation ofβ-aminobutyric acid(BABA)in linseed(Linum usitatissimum L.).Different doses(0,50,100 and 150μM)of BABA were used for seed priming agent and foliar spraying under three soil moisture levels viz.,25%(SM25),45%(SM45)and 65%(SM65).The response variables of both experiments included different agro-botanical traits and oxidative stress indicators such as melondialdehyde content,free proline accumulation,and antioxidant defense in plants.The linseed plants showed water stress at SM25 that reduced plant height,number of branches per plant,time taken to flower initiation and heading,and root and shoot dry weights.Additionally,the number of capsules and seeds per capsule showed a significant decline at SM25,which led to a drastic reduction in 100-seed weight yield in linseed plants in both experiments.However,seed priming and foliar supplementation with of BABA(50–100μM)significantly improved these morpho-agronomical attributes in linseed plants under DS.The results revealed that the BABA was fully active in linseed plants at SM25.Interestingly,the combination of SM25 with BABA significantly improved the antioxidant enzymes superoxide dismutase(SOD),catalase(CAT),ascorbate peroxidase(APX),and peroxidase(POD)activity,which significantly enhanced DS tolerance in linseed plants.These findings might be useful to oil seed breeders and farmers linseed for breeding program in linseed plants as well as sustainable agricultural production of oil seed crop plants.

In Vitro Efficacy Assessment of Botanical Extracts against Botrytis gladiolorum Causing Gladiolus Leaf Blight

An experiment was conducted at the Mycology laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh to find out the efficacy of selected botanical extracts against Botrytis gladiolorum (Bg) causing gladiolus leaf blight. Infected leaves samples were collected from gladiolus farmers’ field and brought to the laboratory for study. Ten selected botanicals were used against the colony growth of (Bg). The botanicals were Mehendi, Chrysanthemum, Basil (Tulsi), Onion, Neem, Bael, Arjuna, Garlic, Aloevera (Ghritkumary) and Turmeric. Botanical extracts were applied at the rate of 5%, 10% and 20%. The radial mycelia growth was found minimum (11.60 mm) in garlic extract treated plate at the dose of 5% at 5 DAI, which was statistically similar with turmeric extract treated (14.00 mm) plate and the inhibition of growth was 60% and 51.72%, respectively. Similar trend was found at 10 DAI and 15 DAI. At 15 DAI, garlic and turmeric extract gave the best result against Bg, which was statistically similar with onion (50.07% inhibition) and mehendi (49.93%). All botanicals showed significantly different results over control and found effective in reducing the mycelial growth at the dose of 10%. At 5 DAI, no radial mycelia growth was found in garlic treated plate, which was statistically similar with onion treated plate, means that the inhibition of growth was 100%. Similar trend was also found at 10 DAI, and 15 DAI but at 15 DAI, onion (30.20 mm) gave the statistically similar results with Garlic (30.10 mm) and the mycelia growth inhibition was (57.70%) and (57.84%), respectively. In case of 20% dose, garlic extract showed the best result at 5 DAI and the radial mycelia growth was found minimum (00.00 mm) which was statistically similar with onion extract treated (00.00 mm) plate and turmeric extract treated plate. The inhibition of growth was 100%. At 15 DAI, the inhibition of fungal growth was found (73.74%), (71.23%) and (66.90%), respectively with treated by turmeric (18.80 mm), garlic (20.60 mm) and onion (23.70 mm).

Green Degumming of Silk by Enzyme Extracted from Natural Sources

The main objective of this work is to degum the silk with natural enzyme in lieu of conventional degumming to make it sustainable. Fibroin and sericin are the main composition of silk. Sericin provides a harsh and stiff effect of silk and decreases the valuable property like luster and whiteness and also leads to uneven dyeing. It is necessary to remove this sericin for the better post processing of silk. The removal process of sericin from silk is called degumming. Usually degumming process is done by using chemicals like soda (Na2CO3), detergent and other chemical staffs. But these chemicals are lethal to the environment. So, if such component found that can be substitute the fatal components and give the same required result or very close then that would be considered as an asset. This work deals with the different enzymes extracted from natural sources such as papaya skin, pineapple skin and guava leaf with variation of enzyme concentrations such as 10 (%), 15 (%) & 20 (%) as well as 35°C 45°C & 55°C temperatures that influence the degumming efficiency. By analyzing the various samples on the basis of degumming efficiency and other tests such as tensile strength, water vapor permeability, pilling and abrasion, crease recovery, whiteness test and spot test are done by standard method, it is found that the enzyme extracted from papaya skin shows the best degumming efficiency 15.9 (%) and other tests also show the good result at 15 (%) concentration and 45°C temperature whereas degumming efficiency 16.6 (%) for conventional process. From this work, it can be concluded that enzyme extracted from papaya skin can be substituted of conventional degumming which is also ecofriendly.

Polyethylene glycol(PEG) mediated expeditious synthetic route to 1,3-oxazine derivatives

Various 1,3-oxazine derivatives were synthesized in high yields,within shorter reaction times using PEG-400 as a safer medium/ mediator.This synthetic route is exceedingly easy and avoids the use of acid/base catalysts.

Synthesis of scl-poly （3-hydroxyalkanoates） by Bacillus cereus found in freshwater, from monosaccharides and disaccharides

BACKGROUND： Polyhydroxyalkanoates are a good substitute for synthetic plastic because they are highly biocompatible, ecofriendly, and biodegradable. Bacteria in freshwater bodies such as rivers, tube wells, and canals are exposed to alternating high and low concentrations of substrates that induce PHA production. METHODS： Fresh water samples were collected for isolation of bacterial strains. Screening of PHA in bacterial cells was performed with Sudan and Nile Red staining. Extracted PHA was characterized by FTIR. RESULTS： In this study, nine bacterial isolates were selected for PHA production on the basis ofphenotypic screening. Their ability to accumulate PHAs was determined using different monosaccharides and disaccharides. Two bacterial isolates Bacillus cereus T1 （KY746353） and Bacillus cereus R3 （KY746354） produced PHAs. Optimal growth of the bacterial strain （T1） was observed in the presence of glucose, followed by maximum production of PHAs （63% PHAs） during the logarithmic phase of growth. B. cereus R3 （KY746354） accumulated 60% PHAs by dry cell weight. CONCLUSION： PHA accumulation was relatively less with fructose, but both strains showed increased production （up to 50%） with sucrose. The polymer produced was characterized by Fourier-transform infrared spectroscopy （FTIR）, which showed that the compound contains short-chain PHAs.

Clean label extraction of bioactive compounds from food waste through microwave-assisted extraction technique-A review

Clean label and green extraction have attained popularity due to elimination of solvent use and reduction in energy consumption.In this regard,microwave assisted extraction have emerged as a novel process for extraction of bioactive compounds.This process observed to consume less time and energy but have higher extraction efficiency.Additionally,the functionality of bioactive compounds has not degraded in this process.Therefore,this article explores the potential of microwave-based extraction as a green and ecofriendly technique.Moreover,it has been coupled with conventional technique(e.g.steam distillation,steam diffusion,hydrodistillation,air hydrodistillation,and hydro-diffusion and gravity)to ease the process and increase the efficiency.Available data highlights the importance of various hybrid techniques(microwave+conventional ones)for the extraction of bioactive compounds from fruit&vegetable waste.