A potential usefulness of raw date pits as an inexpensive solid adsorbent for methylene blue (MB), copper ion (Cu
2+), and cadmium ion (Cd
2+) has been demonstrated in this work. This work was ...conducted to provide fundamental information from the study of equilibrium adsorption isotherms and to investigate the adsorption mechanisms in the adsorption of MB, Cu
2+, and Cd
2+ onto raw date pits. The fit of two models, namely Langmuir and Freundlich models, to experimental data obtained from the adsorption isotherms was checked. The adsorption capacities of the raw date pits towards MB and both Cu
2+ and Cd
2+ ions obtained from Langmuir and Freundlich models were found to be 277.8, 35.9, and 39.5
mg
g
−1, respectively. Surface functional groups on the raw date pits surface substantially influence the adsorption characteristics of MB, Cu
2+, and Cd
2+ onto the raw date pits. The Fourier transform infrared spectroscopy (FTIR) studies show clear differences in both absorbances and shapes of the bands and in their locations before and after solute adsorption. Two mechanisms were observed for MB adsorption, hydrogen bonding and electrostatic attraction, while other mechanisms were observed for Cu
2+ and Cd
2+. For Cu
2+, binding two cellulose/lignin units together is the predominant mechanism. For Cd
2+, the predominant mechanism is by binding itself using two hydroxyl groups in the cellulose/lignin unit.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
► This study assesses the feasibility of chromium uptake onto dolomite. ► Evaluated Δ
G
o
and Δ
H
o
specify that the reaction is spontaneous and exothermic. ► External mass transfer was the initial ...controlling process in the adsorption system. ► Freundlich isotherm fitted the experimental data for all solution temperatures.
The chromium bearing wastewater in this study was used to simulate the low concentration discharge from a major aerospace manufacturing facility in the UK. Removal of chromium ions from aqueous solutions using raw dolomite was achieved using batch adsorption experiments. The effect of; initial Cr(VI) concentration, amount of adsorbent, solution temperature, dolomite particle size and shaking speed was studied. Maximum chromium removal was found at pH 2.0. A kinetic study yielded an optimum equilibrium time of 96
h with an adsorbent dose of 1
g/L. Sorption studies were conducted over a concentration range of 5–50
mg/L. Cr(VI) removal decreased with an increase in temperature (
q
max: 20
°C
=
10.01
mg/g; 30
°C
=
8.385
mg/g; 40
°C
=
6.654
mg/g; and 60
°C
=
5.669
mg/g). Results suggest that the equilibrium adsorption was described by the Freundlich model. The kinetic processes of Cr(VI) adsorption onto dolomite were described in order to provide a more clear interpretation of the adsorption rate and uptake mechanism. The overall kinetic data was acceptably explained by a pseudo first-order rate model. Evaluated Δ
G
o
and Δ
H
o
specify the spontaneous and exothermic nature of the reaction. The adsorption takes place with a decrease in entropy (Δ
S
o
is negative).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The performance of catalysts used for the dry reforming of methane can strongly depend on the selection of active metals, supports and promoters. This work studies their effects on the activity and ...stability of selected catalysts. Designing an economically viable catalyst that maintains high catalytic activity and stability can be achieved by exploiting the synergic effects of combining noble and/or non-noble metals to form highly active and stable bi- and tri-metallic catalysts. Perovskite type catalysts can also constitute a potent and cost effective substituent. Metal oxide supports with surface Lewis base sites are able to reduce carbon formation and yield a greater stability to the catalyst, while noble metal promoters have proven to increase both catalyst activity and stability. Moreover, a successful metal-support-promoter combination should lead to higher metal-support interacrtion, lower reduction temperature and enhancement of the anti-coking and anti-amalgamation properties of the catalyst. However, the effect of each parameter on the overall performance of the catalyst is usually complex, and the catalyst designer is often faced with a tradeoff between activity, stability and ease of activation. Based on the review carried out on various studies, it is concluded that a catalyst design must take into consideration not only the separate effects of the active metal, support and promoter, but should also include the combined and mutual interactions of these components.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Surface reaction methodology was implicated in the optimization of hexavalent chromium removal onto lignin with respect to the process parameters. The influence of altering the conditions for removal ...of chromium(VI), for instance; solution pH, ionic strength, initial concentration, the dose of biosorbent, presence of other metals (Zn and Cu), presence of salts and biosorption–desorption studies, were investigated. It was found that the biosorption capacity of lignin depends on solution pH, with a maximum biosorption capacity for chromium at pH 2. Experimental equilibrium data were fitted to five different isotherm models by non-linear regression method, however, the biosorption equilibrium data were well interpreted by the Freundlich isotherm. The maximum biosorption capacities (
q
max) obtained using Dubinin–Radushkevich and Khan isotherms for Cr(VI) biosorption are 31.6 and 29.1
mg/g, respectively. Biosorption showed pseudo second order rate kinetics at different initial concentrations of Cr(VI). The intraparticle diffusion study indicated that film diffusion may be involved in the current study. The percentage removal of chromium on lignin decreased significantly in the presence of NaHCO
3 and K
2P
2O
7 salts. Desorption data revealed that nearly 70% of the Cr(VI) adsorbed on lignin could be desorbed using 0.1
M NaOH. It was evident that the biosorption mechanism involves the attraction of both hexavalent chromium (anionic) and trivalent chromium (cationic) onto the surface of lignin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Hydroxychloroquine (HCQ) has the potential to be a persistent pollutant in water.•Electrochemical oxidation with BDD anode (EO) degraded HCQ in all tested conditions.•EO led to the release of Cl− ...ions and conversion of organic nitrogen to NO3− and NH4+.•EO combined with UV light or ultrasound enhanced degradation kinetics and efficiency.•Due to higher production of oxidants, EO combined with UV light used much less energy.
In this work, the degradation of hydroxychloroquine (HCQ) drug in aqueous solution by electrochemical advanced oxidation processes including electrochemical oxidation (EO) using boron doped diamond (BDD) and its combination with UV irradiation (photo-assisted electrochemical oxidation, PEO) and sonication (sono-assisted electrochemical oxidation, SEO) was investigated. EO using BDD anode achieved the complete depletion of HCQ from aqueous solutions in regardless of HCQ concentration, current density, and initial pH value. The decay of HCQ was more rapid than total organic carbon (TOC) indicating that the degradation of HCQ by EO using BDD anode involves successive steps leading to the formation of organic intermediates that end to mineralize. Furthermore, the results demonstrated the release chloride (Cl−) ions at the first stages of HCQ degradation. In addition, the organic nitrogen was converted mainly into NO3− and NH4+ and small amounts of volatile nitrogen species (NH3 and NOx). Chromatography analysis confirmed the formation of 7-chloro-4-quinolinamine (CQLA), oxamic and oxalic acids as intermediates of HCQ degradation by EO using BDD anode. The combination of EO with UV irradiation or sonication enhances the kinetics and the efficacy of HCQ oxidation. PEO requires the lowest energy consumption (EC) of 63 kWh/m3 showing its cost-effectiveness. PEO has the potential to be an excellent alternative method for the treatment of wastewaters contaminated with HCQ drug and its derivatives.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Management strategies for children with congenital health diseases (CHDs) should encompass more than just the medical aspect of the disease and consider how heart diseases affect their everyday ...activities and, subsequently, their quality of life (QoL). Global studies witnessed a greater emphasis on studying the QoL associated with CHD. However, there is still a great lag in such data in the Arab region. The purpose of this study was to evaluate QoL in children with CHD using an Arab sample from Jordan. The specific objectives were twofold: (1) to contrast the assessments of children's QoL reported by their parents with those reported by the children themselves, and (2) to assess the factors that influence the QoL of children with CHD.
A total of 79 children aged 2-18 with a confirmed diagnosis of CHD were included in the study, along with their mothers. Of them, 38.0% were girls, 67.1% were diagnosed with non-cyanotic CHD, 58.2% had a severe CHD, 92.4% had undergone at least one operation, 81.0% had repaired defects, 13.9% underwent palliated procedures, and 24.1% were admitted to a neonatal intensive care unit after delivery. The Pediatric Quality of Life Inventory was used to assess QoL of children with CHD. Both children's and parents' reports of QoL were analyzed using paired-sample t-tests, ANOVAs, and multiple linear regression.
Older children reported significantly lower QoL scores, whereas there were no differences in parents-reported QoL scores across different children age groups. There was a divergence in perceptions of QoL between parents-reported and children-reported scores with parents reporting significantly lower scores. The children-reported QoL in this study seemed to be significantly associated with their gender, age, and the presence of learning difficulties, whereas the parent-reported QoL was only associated with the presence of learning difficulties.
Responses from both children and parents need to be considered to understand the similarities and differences between them and to provide further insight into the optimal way to help children with CHD effectively navigate the transition into adulthood. Future research studies of outcomes for survivors of children with CHD are needed to identify high-risk survivors for worse psychosocial functioning and assess prevention measures and treatment interventions to improve their QoL.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Many brown rice samples contained hazardous concentrations of arsenic and cadmium.•Concentration of toxic elements in brown rice is grain-size dependent.•Sum of non-carcinogenic risk ...associated with As and other elements exceeds unity.•Carcinogenic risk from As or Cr in brown rice may be as high as one in every 10,000.•Results can inform the national monitoring program for rice quality and type.
Twenty-two brown rice varieties available in the Qatari market were analyzed for essential and toxic elements by ICP-MS. Found concentrations (µg/kg) were: As: 171 ± 78 (62–343), Cd: 42 ± 60 (4–253), Cr: 515 ± 69 (401–639), Pb: 6 ± 7 (<MDL-26), and U: 0.1 ± 0.5 (<MDL-2). One third of the samples contained high levels of arsenic. Significant differences (p < 0.008) in concentrations were observed for many elements based on both the grains’ country of origin and size. Calculated carcinogenic risk according to published speciation data of inorganic arsenic and chromium(VI) available in the literature for rice is > 1 in million, may possibly be > 1 in 10,000 based on conservatively high brown rice consumption rates of 200 g/d or 400 g/d in Qatar. These elevated risks may be applicable to specific population subgroups with diabetic conditions who consume only brown rice. Non-cancer risks are mainly derived from Mn, V, Se, and Cd with a hazard index > 1 from some brown rice samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AbstractThe construction project information for FM team control and maintenance is vital. However, current practices indicate significant data drops during the handover stage, leading to rework ...during FM systems integration of inaccurate, delivered information. Although challenges in BIM implementation are well studied, there is a current lack of best practices from FM industry experts highlighting challenges with a specific focus on the areas of the data drop. Therefore, the aim is to develop a framework that can reduce data loss and improve data management. The objectives include robust literature review on challenges of information loss during handover phase, management and frameworks; Adopting case study and workshops to identify information loss challenges, framework development and validation with industry experts. This paper adopted a grounded theory approach to explore literature and conducted case studies, including a series of semistructured interviews and a workshop with FM industry experts. The findings show the areas and causes of information loss and how to manage them through the developed information loss management framework (ILMF).
Practical ApplicationsWith the start of any type of project, planning and establishing rules from the beginning facilitates the smooth transition between different phases. Similarly, in construction projects, this research provides guidelines on how facility managers can manage information loss when exchanged through projects’ stages. Furthermore, with the continuing advancements in the construction world, the facility management should be equipped with management and leadership guidelines as presented in the proposed framework to reduce data loss during handover. However, there are cost and contractual issues that prohibit any involvement of the facility manager in early project stages. The results of this study provide an identification of professional practices do’s and do not’s that facilitate the management and development of projects with the support of the latest technologies in the market. Ultimately, developing a guide that adapts international standards. The study’s contribution to knowledge includes the development of a new information loss management framework that adopts BIM and ISO standards after exploring the existing data management frameworks in the literature that lack data loss management as a focus. The framework works as a guide for various stakeholders such as designers, contractors with a focus on FM to facilitates data coordination and management to reduce information loss, its creation and validation were conducted in collaboration with industry experts. Furthermore, its novelty lies in integrating FM role, information management, information loss, address project life cycle, and adopts the ISO 19650 series.
An accurate and fast solid-state transfer switch (SSTS) has the potential to automate conventional utility network. Presently, it consumes most of the transfer time in detecting the condition for ...initiating the transfer process. Recent developments in the power semiconductor devices technology have reduced the switching time to the tune of nanoseconds. Hence, time consumed by the disturbance detection is significant in SSTS. IEEE Std. 1100-2005 and IEEE Std. 446-1995 require fast load transfer for SSTS. Realization of an innovative machine learning technique is implemented on three AVR microcontrollers for each of three phases. The microcontroller executes segmentation of acquired signal and calculates derivative of each segment. From each preprocessed 10-sample segment, mean absolute deviation and energy features are extracted. On the basis of feature values, support vector machine classifier with the linear kernel detects disturbance. Logical OR gate generates transfer enable signal to initiate the transfer process. Results of case studies appreciate the ability of proposed hardware to detect common disturbances in power system under different operating conditions. The hardware provides a feasible solution for SSTS with required accuracy and speed.
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