Halogenated hydrocarbons with high ozone depletion potential (ODP) were banned under Montreal Protocol (1987) due to their detrimental effects on ozone layer that shields the planet against ...ultraviolet radiations. The greenhouse gases (GHG) used in modern refrigeration, air conditioning, and heat pumping systems, are under Kyoto Protocol (1997)’s time-barred permission period. In order to reduce the depletion of ozone and reverse the climate change effects, the European Union legislation (2014) and Paris Accord (2016) are strongly emphasizing the phasing out of the use of harmful synthetic refrigerants. Choice of natural refrigerants makes no net addition of the greenhouse gases (GHG) in the environment. To retrofit and modify existing cooling and heating systems using natural refrigerants, extensive investigations are in progress worldwide. This work reviews timeworn, current and the next-generation refrigerants using Refrigerant Qualitative Parametric (RQP) quantification model to assist the refrigerant choice decision process. It is based on the ratio of arithmetic sums of actual parametric values of refrigerants normalized to equivalent ideal values. This model can help in choosing alternative refrigerants to replace CFCs by HCFCs or HFCs provisionally and finally replacing HCFCs or HFC to low GWP and ODP synthetic and natural refrigerants. A set of 16 refrigerants, both natural and synthetic, as an example, is computed for the standard Vapour Compression Cycle (VCC) based on the proposed model using REFPROP (NIST- 23 standard). The techno-economic parametric values of chosen refrigerants are taken from cited literature, ASHREA safety standards and international environmental legislations, laws and protocols. This paper reports the environment benign natural (CO2, NH3, HCs) and a few synthetic (R-152a, R-1234yf) refrigerants to be the optimal options.
•Refrigerants with ODP and high GWP were banned or facing time barred permission.•A Refrigerant Qualitative Parametric (RQP) quantification model is proposed.•Results show that natural and a few synthetic refrigerants are optimal options.
We present the role of heat and electricity storage systems on the rapid rise of renewable energy resources and the steady fall of fossil fuels. The upsurge in renewable resources and slump in fossil ...fuel consumptions is attributed to sustainable energy systems, energy transition, climate change, and clean energy initiatives. The fast growth of renewables brings new design and operational challenges to transition towards 100% renewable energy goal. Energy storage systems can help ride‐through energy transition from hydrocarbon fuels to renewable sources. Nuclear fusion and artificial photosynthesis are the ultimate Holy Grails for permanent clean energy solutions. Plants harvest light and store it in chemical energy to regulate the food supply chain that may be a guideline for an energy transition from fossil fuels to renewables. Heat and electricity storage devices can account for the periodic nature of solar and wind energy sources. Solar thermal systems for water and space heating are also a viable solution for subzero temperature areas. This study presents the transition of world's energy prospect from fossil fuels to renewables and new advances in energy storage systems.
Soil and water contamination from heavy metals and metalloids is one of the most discussed and caused adverse effects on food safety and marketability, crop growth due to phytotoxicity, and ...environmental health of soil organisms. A hydroponic investigation was executed to evaluate the influence of citric acid (CA) on copper (Cu) phytoextraction potential of jute (
L.). Three-weeks-old seedlings of
were exposed to different Cu concentrations (0, 50, and 100 μM) with or without the application of CA (2 mM) in a nutrient growth medium. The results revealed that exposure of various levels of Cu by 50 and 100 μM significantly (
< 0.05) reduced plant growth, biomass, chlorophyll contents, gaseous exchange attributes, and damaged ultra-structure of chloroplast in
seedlings. Furthermore, Cu toxicity also enhanced the production of malondialdehyde (MDA) which indicated the Cu-induced oxidative damage in the leaves of
seedlings. Increasing the level of Cu in the nutrient solution significantly increased Cu uptake by the roots and shoots of
seedlings. The application of CA into the nutrient medium significantly alleviated Cu phytotoxicity effects on
seedlings as seen by plant growth and biomass, chlorophyll contents, gaseous exchange attributes, and ultra-structure of chloroplast. Moreover, CA supplementation also alleviated Cu-induced oxidative stress by reducing the contents of MDA. In addition, application of CA is helpful in increasing phytoremediation potential of the plant by increasing Cu concentration in the roots and shoots of the plants which is manifested by increasing the values of bioaccumulation (BAF) and translocation factors (TF) also. These observations depicted that application of CA could be a useful approach to assist Cu phytoextraction and stress tolerance against Cu in
seedlings grown in Cu contaminated sites.
Copper (Cu) is an abundant essential micronutrient element in various rocks and minerals and is required for a variety of metabolic processes in both prokaryotes and eukaryotes. However, excess Cu ...can disturb normal development by adversely affecting biochemical reactions and physiological processes in plants. The present study was conducted to explore the potential of gibberellic acid (GA
3
) on fibrous jute (
Corchorus capsularis
L.) seedlings grown on Cu mining soil obtained from Hubei Province China. Exogenous application of GA
3
(10, 50, and 100 mg/L) on 60-day-old seedlings of
C. capsularis
which was able to grow in highly Cu-contaminated soil (2221 mg/kg) to study different morphological, physiological, and Cu uptake and accumulation in different parts of
C. capsularis
seedlings. According to the results, increasing concentration of GA
3
(more likely 100 mg/L) alleviates Cu toxicity in
C. capsularis
seedlings by increasing plant growth, biomass, photosynthetic pigments, and gaseous exchange attributes. The results also showed that exogenous application of GA
3
reduced oxidative stress in
C. capsularis
seedlings by the generation of extra reactive oxygen species (ROS). The reduction in oxidative stress in
C. capsularis
seedlings is because that plant has strong enzymatic antioxidants superoxidase dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT), which ultimately increased their activities to overcome oxidative damage in the cells/tissues. In addition to the plant growth, biomass, and photosynthesis, foliar application of GA
3
also helps to increase metal (Cu) concentration in different parts of the plants when compared to 0 mg/L of application of GA
3
. From these findings, we can conclude that foliar application of GA
3
plays a promising role in reducing ROS generation in the plant cells/tissues and increased phytoextraction of Cu in different plant parts. However, more investigation is needed on field experiments to find a combination of GA
3
with a very higher concentration of Cu using fibrous
C. capsularis
.
The optical solitary waves explain non-dispersive and non-diffractive spatiotemporal localized waves envelopes promulgating in the media of optical Kerr. These propagations are generally described by ...the nonlinear Schrö dinger equation. The modified extended mapping technique is utilized to assemble the solitons, solitary waves and rational solutions of time-dependent dimensionless paraxial wave equation. The obtained different sorts of wave solutions encompass key applications in physics and engineering. By giving appropriate values to parameter, special sorts of solitary waves configuration can be displayed graphically. The physical interpretation of the solution can be understood through the structure. The stability of this wave equation is investigated via using modulational instability analysis which authenticates that all soliton solutions are stable and exact. Several analytical results and working out have confirmed the strength and efficacy of the current technique.
Although community practices towards disposal of expired and unused medications vary globally, the phenomenon is neglected specifically in developing countries. We, therefore, aimed to assess the ...disposal practices of unused and expired pharmaceuticals among the general public in Quetta city, Pakistan.
A questionnaire-based, cross-sectional survey was conducted among 830 respondents in Quetta city, Pakistan. A pre-validated, structured questionnaire was used for data collection. Data were coded and analyzed by Statistical Package for Social Science (SPSS) version 26. Both descriptive and inferential statistics were sued and p<0.05 was taken as significant.
Almost 87% of the respondents had unused medicines at their homes and reusing the medications was the purpose of medicine storage (50%). Medicines were mostly kept in refrigerators (36.0%) followed by bedrooms (28.8%). Fifty percent of the respondents never checked the expiry date before using the medications. The procedure to dispose of nearly expired or expired medicines was unknown to 88% of the respondents and for those reasons, medicines were disposed either in household trash or flushed in the toilet or sink. Interestingly, medicines were kept at home even after being expired by 27% of the respondents. Income was associated with reason of storing medicines (p = 0.004; φc = 0.402) while educational status had significant associations with storage of medications (p = 0.002; φc = 0.399), reading about storage instructions (p = 0.008; φc = 0.452) and checking expiry date before purchasing and using the medicines (p = 0.007; φc = 0.114 and p = 0.001; φc = 0.100) respectively.
Improper storage and disposal of unused and expired medications is a common practice among study respondents and raised serious concerns. Findings of the current study call upon immediate development and implementation of the strategies to promote awareness and strengthen the pharmaceutical waste management program at the societal level.
Aims
Increasing evidence shows that root system growth is strongly affected by different nitrogen (N) signals and the available N source in the rhizosphere. Molybdenum (Mo), an essential trace ...element, plays a key role in N assimilation and metabolism. However, Mo efficacy may vary with different N sources. The present experiment was performed to examine the Mo role on root system growth in winter wheat under different N sources.
Methods
A hydroponic experiment was conducted consisting of two winter wheat cultivars; Mo-efficient (97003) and Mo-inefficient (97014) under two Mo levels (0 and 1 μM) and three N sources (NO
3
−
, NH
4
NO
3
or NH
4
+
).
Results
The results showed that Mo supply increased root dry weight and other morphological traits, nitrate reductase (NR) activities, nitric oxide (NO) contents, total N concentration and the expressions of nitrate transporter (
NRT
) genes under various N sources, however, such effects were in the order of NH4NO3 > NO
3
−
> NH
4
+
, suggesting that Mo fertilizer shows more complementary effects towards NO
3
−
form of N than sole NH
4
+
in winter wheat.
Conclusions
These findings imply that Mo plays a significant role in increasing the root system growth of wheat through NO production, efficient N uptake and assimilation, and regulation of
NRT
gene expressions, especially under NH4NO3 nutrition.
Different nitrogen (N) sources have been reported to significantly affect the activities and expressions of N metabolism enzymes and mineral elements concentrations in crop plants. However, ...molybdenum-induced effects in winter wheat cultivars have still not been investigated under different N sources. Here, a hydroponic study was carried out to investigate these effects on two winter wheat cultivars ('97003' and '97014') as Mo-efficient and Mo-inefficient, respectively, under different N sources (NO
, NH
NO
, and NH
). The results revealed that the activities of nitrate reductase (NR) and nitrite reductase (NiR) followed the order of NH
NO
> NO
> NH
sources, while glutamine synthetase (GS) and glutamate synthase (GOGAT) followed the order of NH
> NH
NO
> NO
in both the wheat cultivars. However, Mo-induced effects in the activities and expressions of N metabolism enzymes under different N sources followed the order of NH
NO
> NO
> NH
sources, indicating that Mo has more complementary effects towards nitrate nutrition than the sole ammonium source in winter wheat. Interestingly, under -Mo-deprived conditions, cultivar '97003' recorded more pronounced alterations in Mo-dependent parameters than '97014' cultivar. Moreover, Mo application increased the proteins, amino acids, ammonium, and nitrite contents while concomitantly decreasing the nitrate contents in the same order of NH
NO
> NO
> NH
sources that coincides with the Mo-induced N enzymes activities and expressions. The findings of the present study indicated that Mo plays a key role in regulating the N metabolism enzymes and assimilatory products under all the three N sources; however, the extent of complementation exists in the order of NH
NO
> NO
> NH
sources in winter wheat. In addition, it was revealed that mineral elements profiles were mainly affected by different N sources, while Mo application generally had no significant effects on the mineral elements contents in the winter wheat leaves under different N sources.
Transitioning from fossil fuels to renewable energy ensures a sustainable and green future by limiting greenhouse gas emissions and their nuisance effects. This study proposes a polygeneration system ...that harnesses renewable energy to produce multiple energy vectors simultaneously and equipped with storage to mitigate the impact of intermittent weather. To perform dynamic analysis, proposed system has been modeled, optimized, and simulated using the transient simulation software TRNSYS®. The designed model has been optimized in GenOpt, linked with TrnOpt, under the weather conditions of Gujrat, Pakistan. The power system is energized by solar photovoltaic, thermal and wind power to produce cooling, heating, electricity, hydrogen, and oxygen as energy vectors, and also provides electric, hydrogen, and thermal storage. Prime movers utilized for energy conversion consists of evacuated glass tube collector, photovoltaic panels, wind energy conversion system, fuel cell, electrolyzer, and absorption chiller, which facilitate air-conditioning, space and water heating, electric power supply for electric vehicle, building load & national grid, hydrogen for internal combustion engines, fuel cell electric vehicle and industrial applications, as well as oxygen for hospitals. The study has shown that thermal collector has 68% efficiency, a solar fraction 0.78, peak outlet temperature 143.77 °C, and generates a total 1399656.25 kJ thermal energy. The wind and photovoltaic systems have maximum efficiencies values 52.24 % and 10.90 % respectively, resulting in the production of 44.8 MWh electric energy. Embracing the synergy of solar and wind power in a polygeneration system holds the key to a sustainable and eco-friendly future.
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•Polygeneration from renewable energy enables production of cooling, heating, electricity, water, hydrogen, and oxygen.•Dynamic modeling using transient simulation software TRNSYS® and optimized using GenOpt linked with TrnOpt.•Multiple prime movers for energy such as EGTC, PV panels, WECS, fuel cell, electrolyzer, and absorption chiller.•Performance metrics: EGTC 68 %, solar fraction 0.78, WECS 52.24 %, PV 10.90 % and electrolyzer 95.7 % efficiency.
Cadmium (Cd) toxicity causes severe perturbations in nitrogen (N) uptake and assimilation, and thereby interrupts normal plant growth. Molybdenum (Mo), a necessary trace element, plays important ...roles in N metabolism through regulating N assimilatory enzymes activities and expressions in higher plants. Taking this into account, a pot experiment was performed to explore the role of Mo in alleviating Cd-induced inhibitory effects on physio-biochemical processes, N metabolism, yield attributes and grain quality characters of two fragrant rice cultivars; Guixiangzhan and Meixiangzhan-2. Both the fragrant rice cultivars were treated with two levels of each Cd concentrations (0 and 100 mg/kg) and Mo treatments (0 and 0.15 mg/kg). The results revealed that Cd toxicity significantly reduced (p < 0.05) plant dry biomass, gaseous exchange attributes, chlorophyll contents, N utilizing and assimilatory enzymes activities, 2-acetyl-1-pyrroline (2AP) contents and grain yield in both cultivars; however, more severe inhibitions were observed in Meixiangzhan-2 than Guixiangzhan. Nevertheless, Mo application alleviated Cd stress and enhanced 2AP content and grain yield by 75.05% and 67.94% in Guixiangzhan and 87.71% and 83.51% in Meixiangzhan-2, respectively compared with no Mo application. Moreover, Mo application improved photosynthesis, chloroplast configuration, soluble protein and proline contents and also strengthened the N assimilatory pathway through efficient NO3− utilization, higher nitrate reductase, nitrite reductase, glutamine synthetase and glutamate synthase activities and transcript levels under Cd stress. Collectively, our results imply that Mo-induced enhancement in N utilization and assimilation improved yield and grain quality characters of fragrant rice cultivars under Cd stress.
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•Molybdenum (Mo) and cadmium (Cd) interaction was examined in fragrant rice cultivars.•Cd toxicity severely hampered N metabolism and growth performance of fragrant rice.•Mo strengthened photosynthetic apparatus and N assimilatory pathway under Cd stress.•Mo-induced enhancement in N assimilation improved quality and yield of fragrant rice.
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