Molybdenum disulfide (MoS2) with unique electronic and physical properties has attracted great interest in the field of next-generation optoelectronic and photonic devices for societal benefits. In ...view of considering the great challenge in scaling the monolayer MoS2, the current focus is on improving the performance of few-layer MoS2-based optoelectronic and photonic devices. Here, we report multifunctional large area-grown few-layer MoS2 for the photoresponse and detection of organic pollutants. The few-layer MoS2 (thickness of around 4 nm) has been successfully synthesized over highly doped p-type Si via the chemical vapor deposition technique, and their optical properties have been studied using Raman and photoluminescence spectroscopy. Here, we report the photoresponse of a pristine few-layer MoS2/Si heterojunction under low-power white light illumination (0.15 mW cm–2) with 0.1413 A W–1 photoresponsivity at −2 V. This photoresponsivity is the best to our knowledge under white light illumination condition concerning light intensity. Further, few-layer MoS2 over Si has been successfully demonstrated as a surface-enhanced Raman spectroscopy (SERS) substrate for the ultrasensitive detection of Rhodamine 6G (R6G) at nanomolar concentration, which is the highest detection limit for R6G using pristine MoS2 to the best of our knowledge. Additionally, we also examined the treatment of adsorbed R6G over few-layer MoS2 in the presence of water under visible light illumination for reusability of the SERS substrate with repeated detectability.
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•An extremely simple and effective strategy for directional growth of poly (3-hexylthiophene) nanowires.•Macroscopic alignment of P3HT nanowires was obtained using off – center spin ...coating.•GIXD and HR-TEM demonstrated highly crystalline π–π stacked lamellar structure.•H – like aggregation of polymer chains with extended conjugation length in P3HT-DCM.•Highly oriented and crystalline P3HT nanowires film exhibited average mobility of 0.053 cm2V−1s−1.
Controlling the morphology, molecular packing and alignment of conjugated polymer remain a primary challenge that hinders their widespread applications in electronic and optoelectronic devices. Here, we have demonstrated an extremely simple and effective strategy for nucleation and growth of highly crystalline and aligned nanowires of regioregular poly (3-hexylthiophene) (P3HT) in the solvent that exhibits a remarkable enhancement in charge transport properties. We have used the combination of marginal solvent (dichloromethane) and ultrasonication to obtain highly crystalline, aligned and ordered nanowires of P3HT by means of off-center spin coating and compared with their on-center counterparts also. Macroscopically ordered and aligned nanowires of P3HT are confirmed by atomic force microscopy (AFM) and polarized optical microscopy (POM). Grazing incidence X-ray diffraction (GIXD) and high-resolution transmission electron microscopy (HR-TEM) demonstrated highly crystalline π–π stacked lamellar structure. The organic field-effect transistors (OFETs) based on highly oriented and crystalline P3HT nanowires exhibited a 50-fold enhancement in charge carrier mobility (average mobility 0.053 cm2V−1s−1) compared to OFETs based on P3HT film prepared in a good solvent (chloroform), measured under the ambient condition. The results are further supported by UV–vis spectroscopy, cyclic voltammetry, and theoretical calculation. Our study is a promising strategy for achieving large-scale aligned nanostructures of solution processable conjugated polymer film to enable high-performance organic electronic devices.
•This study assesses climate change vulnerability of Himalayan communities and their potential to adapt to these changes.•The assessment is based on the five capitals of sustainable livelihood ...framework.•The study results that the households reside away to district head quarter are in disadvantageous position and more vulnerable than those households, who reside near to district head quarter in mountainous settings.
This study evaluated the climate change vulnerability of Himalayan communities, and their potential to adapt to these changes, through assessing their perceived reactions and counter-actions to climate change. The evaluation was conducted through proposing and testing indices for vulnerability (Climate Vulnerability Index – CVI) and adaptation (Current Adaptive Capacity Index – CACI) based on the assumption that a community is an active dynamic entity and has tremendous capability to address the impacts of climate change through an ability to make adjustments based on perceived experiences. Both CVI and CACI include the five forms of capital leading to sustainable livelihood, i.e. human, natural, financial, social and physical capital, and were assessed for each of these forms of capital based on the IPCC framework of vulnerability assessment and its three dimensions (exposure, sensitivity, adaptive capacity). Data for the analysis were collected from randomly selected households located away from district headquarters (ADH) and near district headquarters (NDH). Each dimension was measured based on associated socio-environment-specific indicators for assessing vulnerability and sustainability at community level. The results showed that ADH households had higher human capital and natural capital vulnerability than NDH households. In contrast, NDH households had higher social capital and financial capital vulnerability than ADH households. Overall, ADH households had greater vulnerability than NDH households.
These results improve understanding of the environmental and socio-economic changes affecting rural livelihoods and the measures needed to address their specific vulnerabilities by addressing bottlenecks in education and training facilities for skill up-grading, increasing interaction opportunities through local functions and creating opportunities for income generation and effective market and farm linkages. An attempt was made to reduce the gap between bottom-up understanding and top-down policies by suggesting precautionary and ongoing adaptation practices for the communities studied, leading to effective and efficient addressal of vulnerabilities. Vulnerability in the study context was taken to mean externally driven change leading to disturbance in the human environment that could alter internal and external livelihood settings.
Leaf functional traits support plant survival and growth in different stress and disturbed conditions and respond according to leaf habit. The present study examined 13 leaf traits (3 morphological, ...3 chemical, 5 physiological, and 2 stoichiometry) of nine dominant forest tree species (3 coniferous, 3 deciduous broad-leaved, 3 evergreen broad-leafed) to understand the varied response of leaf habits. The hypothesis was to test if functional traits of the conifers, deciduous and evergreen differ significantly in the temperate forest and to determine the applicability of leaf economic theory i.e., conservative vs. acquisitive resource investment, in the temperate Himalayan region. The attributes of the functional traits i.e., leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf water content (LWC), stomatal conductance (Gs), and transpiration (E) followed the order deciduous > evergreen > coniferous. Leaf carbon and leaf C/N ratio showed the opposite pattern, coniferous > evergreen > deciduous. Chlorophyll (Chl) and photosynthetic rate (A) were highest for evergreen species, followed by deciduous and coniferous species. Also, structural equation modelling determined that morphological factors were negatively related to physiological and positively with chemical factors. Nevertheless, physiological and chemical factors were positively related to each other. The physiological traits were mainly regulated by stomatal conductance (Gs) however the morphological traits were determined by LDMC. Stoichiometry traits, such as leaf C/N, were found to be positively related to leaf carbon, and leaf N/P was found to be positively related to leaf nitrogen. The result of the leaf functional traits relationship would lead to precise prediction for the functionality of the temperate forest ecosystem at the regional scale.
•Morphological, physiological, and stoichiometric traits do changes with seasons.•Major temperate ban oak forest (BOF) tree species are resource conservative.•Specific leaf area regulates the ...resource capture and defense strategy in BOF.•Transpiration rate accounts gas exchange in BOF.•Leaf nitrogen content accounts photosynthetic and resource utilization in BOF.
Leaf functional traits determine a plant’s survival and growth. Variation in leaf traits control the functioning of forest ecosystem. The study examines the variation in 18 leaf traits (4 morphological, 6 physiological, 6 biochemical, and 2 stoichiometry) of 3 dominant evergreen broadleaved tree species (Quercus leucotrichophora, Rhododendron arboreum, and Myrica esculenta) of Ban Oak forests (BOF) of Garhwal Himalaya. The aim of the study is to understand the resource utilization plant strategy of major tree species of BOF and determining the impact of seasonality and elevation on leaf traits. Leaf traits data were collected during three seasons (winter, summer and monsoon) within two altitudes (1400–1700 amsl and 1701–1980 amsl) for two years (2019–2021). Thirty-six individuals from each of the three major tree species were selected for measurement on leaf traits for the three seasons of two years. Results showed that specific leaf area, leaf mass per area, photosynthesis rate, stomatal conductance, intercellular CO2, transpiration rate, leaf phosphorus, potassium concentration, and photosynthetic nitrogen use efficiency were higher during monsoon season. However, intrinsic water use efficiency and leaf nitrogen concentration were higher during summer season, and leaf dry matter content, water use efficiency, and leaf C/N were higher in winter season. Structural Equation Modelling (SEM) was used to established the relationship between plant strategies, i.e. resource capture and defense (RCD), gas exchange (GE), photosynthetic and resource utilization (PRU), and nutrient cycle and limitation strategy (NCL). Among the morphological, physiological, biochemical and stoichiometry traits, specific leaf area, transpiration rate, leaf nitrogen concentration, and leaf C/N ratio, were having positive relationship with RCD, GE, PRU and NCL, respectively. Result demonstrates that all the three major species of BOF had resource conservative strategies. Q. leucotrichophora was major species for forest functioning, whereas M. esculenta had higher resource uptake efficiency. Overall, leaf traits were varied with different species and seasonal changes facilitate an adaptive role in a plant's survival under the existing microclimatic condition. The findings of the study provides insight into changes in leaf traits and the plant strategies at the temperate forests of the Himalayas and provide inputs for projection of future changes in leaf attributes and the environment's adaptation at Himalaya and regional level.
•Most of the NbS of Tropical drylands of India are not follow the IUCN standard criteria.•The Identified NbS are baised towards environmental services than addressing social needs of the ...people.•Improved NbS interventions requires intensive enagement of stakeholders for addressing social causes.
Nature-based Solutions (NbS) is a flexible, adaptable, and multi-functional strategies employed to address climate change. However, all the claimed NbS are actually do not adhere the criteria of being NbS. Therefore, present study analysed 87 articles to appraise adherence of potential NbS as per the IUCN Global Standard, along with evaluation of flow of associated ecosystem services (ES). The review identified 39 interventions, out of which only twelve interventions adhered the criteria of NbS. Among the classified NbS, two interventions, namely, sustainable forest management (SFM) (80.83%) and haveli rejuvenation (75.61%) strongly adhered to the IUCN Standard. Lack of adherence in the non-classified NbS interventions was mainly attributed to absence of information on inclusive governance, monitoring and associated trade-offs. The identified 39 interventions were also observed to be enhancing a total of 37 ES, evaluated through 37 distinct indicators i.e. different and enhanced flow of ES were observed by the different NbS. However, the majority of classified NbS were biased towards flow of environmental services than social services. Present study results that all claimed NbS cannot fulfilled the intended objectives of NbS and thus cannot be classified under the NbS as per global standard. Moreover, assessing the flow of associated ES may be an additional support to broaden the scope of NbS implementation. Therefore, present study also highlights to integrate the flow of ES along with the adherence criteria of NbS. Moreover, the review also facilitate to understand constraints associated with the implementation of potential NbS interventions and thus, suggests considering wider aspects in the future researches for assessing the implementation of NbS.
•Soil respiration (Rs) varied across various Himalayan temperate forests.•Rs were highest for Picea smithiana and Abies pindrow of Western Mixed Coniferous Forest.•The lowest Rs were observed for ...Cedrus deodara of Low-Level Blue Pine Forest.•Soil respiration was positively influenced by soil and air temperature.
Soil respiration (Rs) is a natural phenomenon of CO2 emission and has a significant contribution in regulating the carbon cycle. Identifying the drivers that influence soil CO2 emissions are essential for assessing the potential impacts of change on the Carbon (C) cycle in the forest ecosystem. The present study estimated soil respiration and evaluated different drivers i.e., soil, vegetation, climate, and topography by collecting data from twelve sites (forest sub-types) of temperate forests widely distributed in the Indian Western Himalayan Region. Total 432 observations were recorded from six individuals of two major tree species of twelve sites at three locations below the crown across the selected sites. ANOVA, Regression and Structural Equation Modelling (SEM) were used to analyze the data. No significant variance in Rs between the individual trees of the selected major species and between the major species of a site were observed, however, there was a significant difference between the sites for Rs. SEM of the temperate forest explains that various climatic (maximum and minimum temperature), vegetation (density and abundance) and topographical factors (altitude, longitude and latitude) were intricately related to the functioning of the temperate forests, however Rs was positively influenced by soil temperature, maximum air temperature, and altitude, and negatively by abundance. The study concludes that Rs varied differentially across the various forest sub-types of temperate forests and increases with increase in temperature and altitude. The results would provide information for estimating the feedback of the soil carbon fluxes to future climate change and also the development of carbon management policies for forest ecosystems.
Abstract
The higher operating temperature of metal oxide and air instability of organic based NO
2
sensor causes extremely urgent for development of a reliable low cost sensor to detect NO
2
at room ...temperature. Therefore, we present a fabrication of large area Polymer/GO nano hybrid thin film for polymer thin film transistors (PTFTs) based NO
2
sensors assisted via facile method named ‘spreading-solidifying (SS) method’, grown over air/liquid interface and successive investigation of effect of NO
2
on film via several characterizations. The PTFTs sensor has demonstrated swift and high response towards low concentration of NO
2
gas with air stability and provided real time non-invasive type NO
2
sensor. Herein, we are reporting the nanohybrid PBTTT/GO composite based PTFT sensor with good repeatability and sensor response for low concentration NO
2
. The thin film grown via SS technique has reported very good adsorption/desorption of target analyte having response/recovery time of 75 s/523 s for 10 ppm concentration of NO
2
gas. It has been observed that % change in drain current (sensor response) saturated with increasing concentration of NO
2
. The transient analysis demonstrates the fast sensor response and recovery time. Furthermore, in order to understand the insight of high performance of sensor, effect of NO
2
on nanohybrid film and sensing mechanism, an
in situ
investigations was conducted via multiple technique viz. spectral, electronic, structural, and morphological characterization. Finally, the performance of sensor and the site of adsorption of NO
2
at polymer chains were argued using schematic diagram. This work shows the simple fabrication process for mass production, low cost and room temperature operated gas sensors for monitoring the real-time environment conditions and gives an insight about the sensing mechanism adsorption site of NO
2
.
A facile method for the fabrication of highly oriented hybrid thin films of conjugated polymer (CP) with graphene oxide (GO) as 2D nano-filler over the high surface tension liquid substrate by ...floating film transfer is being reported. Formation of the self-assembled oriented hybrid thin film has been validated using multiple characterization techniques. Hybrid thin films thus prepared have been used for the fabrication of organic field effect transistors (OFETs) followed by investigation of anisotropic charge carrier transport. OFETs made with hybrid films oriented in channel direction exhibited the superior device performance with >6 fold augmentation in field effect mobility (μ) and one order improvement in on/off ratio as compared to that of devices based on pristine CP. However, pristine polymer shows 2.2 fold enhancement in mobility and one order augmentation in on/off ratio in parallel orientation as compared to the corresponding perpendicularly oriented films. Thus, our study has elucidated a path to obtain oriented, aligned, and self - assembled hybrid films for further improvement in the device performance aiming towards the applications in organic electronics.
(a) Surficial flow of hybrid solution on the liquid substrate depends on spreading coefficient S which is directly connected S=γliq−γsol−γliq−sol. (b) Positive S results in a surficial flow of solution. However viscous force (Fv) act as compressive force, results in formation of uniform compact, aligned and oriented hybrid thin film in star shape. HR-TEM and transfer curve depicts the GO induced alignment, orientation of polymer chain and high mobility hybrid film. Display omitted
•Cultural Ecosystem Services in Community Forests vary with socio-demography attributes of households.•Traditional ecological knowledge is pivotal for the forest management in community forests of ...Himalaya.•Limited recognition of Cultural Ecosystem Services is attached to human well-being in community forest of Himalya.
Cultural ecosystem services (CES) of community forests (CFs) contribute to human welfare. However, limited information is available about the relationship between traditional ecological knowledge (TEK) and households’ attributes with CES. The present study evaluates the relationship between TEK and socio-cultural values of households with CESs across community forests (CFs), specifically Van Panchayats (VPs), in the western Himalayan region, India. The perceived relevance of six CESs attributes (Intellectual, Inspirational, Cultural, Recreational, Spiritual and Aesthetic) was collected from 104 randomly selected households, followed by eight focused group discussions (8 FGDs) and ten Key Informant Interviews (10 KIs) in VPs of two different forest types (Himalayan Moist Temperate Forest, HMTF, and Sub- Tropical Pine Forest, STPF). The Garret ranking analysis reveals that local communities in the HMTF valued cultural attributes, such as folk and nature rituals, and pristine essence and serenity of aesthetic attributes as the most important CESs. However, the communities in the SPTF valued Recreational attributes, such as Ecotourism, and intellectual attributes, such as VPs management meetings more highly. Out-migration, forest degradation and human-wildlife conflict were identified as major threats to the socio-ecological systems and were adversely affecting the CESs, particularly aesthetic, sense of belongingness, and community harmony. The Kruskal-Wallis’s test showed a significant influence (p < 0.005) of socio-demographic variables on the prioritization of perceived CES. The research underscores the importance of acknowledging and appreciating the cultural services of the local communities. This recognition of CES is crucial for enhancing and refining the forest management for achieving conservation and sustainable development of forests.
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