Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; : 176206, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39278498

RESUMO

Biogas, a sustainable alternative to fossil fuels, addresses issues of non-renewability and accessibility. Its structural similarity to fossil fuels makes it a potent option for energy systems. With this in mind, this paper discusses a novel trigeneration system that utilizes biogas and Liquefied natural gas cooling to produce methanol, electricity, cold water, hot water, oxygen, and natural gas. The system integrates various components such as a biogas burner, Kalina cycle, organic Rankine cycle, liquefied natural gas liquid gasification cycle, proton exchange membrane electrolyzer, and methanol synthesis unit. Simulation via Aspen HYSYS software includes an analysis of energy, exergy, economic, and environmental aspects. Efficiency assessment in single generation, cogeneration, trigeneration, and chemical trigeneration modes concludes chemical trigeneration as most efficient, with the proton exchange membrane electrolyzer being the most efficient subsystem. Key variables like Kalina cycle evaporator temperature, gas flow rate to the methanol reactor, and organic Rankine cycle working fluid pressure are assessed. Predictions on thermodynamic, environmental, and economic behaviors, along with their fluctuations, are made. Using a thermoeconomic approach, the economic analysis determines an exergy unit cost of 59.79 $/GJ and a total cost rate of 2764 $/h. Overall, this work presents a novel and efficient chemical trigeneration system that utilizes biogas and LNG cooling to produce multiple products.

2.
Cureus ; 15(1): e33968, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36820125

RESUMO

Introduction The incidence of retinal detachment in the general population is 0.08%, it has been reported to reach 0.7% or higher following cataract surgery. One of the most important risk factors for retinal detachment is posterior capsular rupture during cataract surgery. Additional risk factors include high myopia, history of ocular trauma, young age, male sex, and diabetes. In this study, we aimed to investigate the incidence and risk factors of retinal detachment following cataract surgery in patients treated at our hospital. Materials and methods This retrospective cohort study was conducted at King Abdulaziz University Hospital (KAUH), a tertiary center in Jeddah, Saudi Arabia. The medical records of 365 patients (365 eyes) who underwent cataract surgery from 2017 to 2021 were reviewed. Results The average age of the 365 patients was 63 years, and 47.7% (n=174) of patients were male. The incidence of retinal detachment was 3.3% (n=12). The risk of RD was 2.8 times higher for the right eye than for the left eye. The incidence of RD was significantly more in eyes with intraoperative posterior capsular rupture, zonular dehiscence, corneal trauma, and surgery combined with anterior vitrectomy than in other eyes. The most common complication of cataract surgery is corneal edema, which was observed in 22.7% of the eyes; our analysis revealed a significant relationship between corneal edema and the duration of surgery. Conclusion In our study, we highlighted the higher incidence of retinal detachment compared to those in other studies; most cases occurred one month postoperatively.

3.
Ecotoxicol Environ Saf ; 206: 111396, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33039852

RESUMO

Salinity is a key worldwide ecological restriction to sustainable crop production and food security. Various methods were used for inducing salinity tolerance including biotechnological approaches or application of stress tolerance-inducing substances. Silicon supplementation has a decisive role in alleviating of salinity injury, however, the definite mechanisms behind stay scantily understood, and must be examined. The imperative roles of sodium metasilicate (Si, 100 ppm) application methods (foliar spraying at 100 mg/l; soil additive at 100 mg/kg soil; foliar spraying at 100 mg/l plus soil additive at 100 mg/kg soil), in improving growth and essential oil yield, maintaining water status, activating antioxidant system, and keeping ion homeostasis of salt affected-sweet basil (6000 mg NaCl/kg soil) were studied. Salinity induced a notable increase in oxidative biomarkers, coupled with higher osmolyte concentration and osmotic potential (OP) values, as well as increased superoxide dismutase and peroxidase activities. Alternatively, sweet basil growth, essential oil yield, and catalase activity were reduced under salinity. Furthermore, salinity aggravated ion imbalance, decreased photosynthetic pigment and disrupted the plants' water status. Silicon application drastically increased osmolyte accumulation associated with sustained water status, increased OP, and improved osmotic adjustment (OA) capacity. Additionally, Si application enhanced antioxidant aptitude associated with decreased oxidative biomarkers and improved growth, photosynthetic pigment, and essential oil yield. Greater outcomes were achieved with the foliar spraying method, compared with other application methods. Salinity stress evoked modification in protein assimilation capacity and possibly will withdraw protein biosynthesis and reduce total protein band number; however, Si application may adjust the expression of salinity inducible proteins. Foliar spraying of Si with or without soil additive accelerates the expression of peroxidase isozyme over salinized or control plants. Collectively, Si foliar spraying alleviated salinity-related injuries on sweet basil by maintaining water status, increasing osmolyte assimilation, improving OA, enhancing redox homeostasis, and antioxidant capacity.


Assuntos
Antioxidantes/metabolismo , Homeostase/efeitos dos fármacos , Ocimum basilicum/efeitos dos fármacos , Estresse Salino/efeitos dos fármacos , Silicatos/farmacologia , Água/metabolismo , Ocimum basilicum/metabolismo , Óleos Voláteis/metabolismo , Oxirredução , Peroxidase/metabolismo , Fotossíntese/efeitos dos fármacos , Tolerância ao Sal/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Solo/química , Superóxido Dismutase/metabolismo
4.
Saudi J Biol Sci ; 27(11): 3072-3078, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33100867

RESUMO

Global climate change and increased population caused significant depletion of freshwater especially in arid and semi-arid regions including Saudi Arabia. Saline water magnetization before irrigation may help in alleviating the adverse effects of salinity on plants. The current study aimed to examine the potential beneficial effects of water magnetization and soil amendments on growth, productivity, and survival of Calendula officinalis L. plants. Three types of water (tap water "control", well water, and magnetized well water) and two types of soil amendments (Fe2SO4 and peat moss) were examined. Our results showed that irrigating C. officinalis plants with saline well water (WW) adversely affected growth and flowering as compared to tap water (TW). However, plants irrigated with magnetized water (MW) showed significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with WW. Furthermore, mineral contents and survival of C. officinalis plants irrigated with MW were higher than those irrigated with TW. Irrigation with MW significantly reduced levels of NA+ and Cl- ions in leaves of C. officinalis plants indicating the role of magnetization in alleviating harmful effects of salinity. The current study showed that water magnetization enhanced water quality and increased plant's ability to absorb water and nutrients. Further studies are needed to examine the possibility of irrigating food crops with magnetized water.

5.
Plants (Basel) ; 9(9)2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32937748

RESUMO

Soil salinity is the main obstacle to worldwide sustainable productivity and food security. Zinc sulfate (Zn) and paclobutrazol (PBZ) as a cost-effective agent, has multiple biochemical functions in plant productivity. Meanwhile, their synergistic effects on inducing salt tolerance are indecisive and not often reported. A pot experiment was done for evaluating the defensive function of Zn (100 mg/L) or PBZ (200 mg/L) on salt (0, 50, 100 mM NaCl) affected pea plant growth, photosynthetic pigment, ions, antioxidant capacity, and yield. Salinity stress significantly reduces all growth and yield attributes of pea plants relative to nonsalinized treatment. This reduction was accompanied by a decline in chlorophyll, nitrogen, phosphorus, and potassium (K+), the ratio between K+ and sodium (Na+), as well as reduced glutathione (GSH) and glutathione reductase (GR). Alternatively, salinity increased Na+, carotenoid (CAR), proline (PRO), ascorbic acid (AsA), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) over nonsalinized treatment. Foliar spraying with Zn and PBZ under normal condition increased plant growth, nitrogen, phosphorus, potassium, K+/Na+ ratio, CAR, PRO, AsA, GSH, APX, GR, and yield and its quality, meanwhile decreased Na+ over nonsprayed plants. Application of Zn and PBZ counteracted the harmful effects of salinity on pea plants, by upregulating the antioxidant system, ion homeostasis, and improving chlorophyll biosynthesis that induced plant growth and yield components. In conclusion, Zn plus PBZ application at 30 and 45 days from sowing offset the injuries of salinity on pea plant growth and yield by upregulating the antioxidant capacity and increasing photosynthetic pigments.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA