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Researchers have made significant efforts over the past few decades to understand adsorption by developing various simple adsorption isotherm models. However, though many contaminants usually occur as multicomponent mixtures in nature, multicomponent adsorption isotherms have received limited attention and remain an area of inadequate research. We have presented here in a new multicomponent adsorption isotherm model, named the Jeppu Amrutha Manipal Multicomponent (JAMM) isotherm, that can alleviate this problem. We first developed the JAMM multicomponent isotherm using our experimental data sets of arsenic and fluoride competitive adsorption on activated carbon. We then tested the JAMM multicomponent isotherm for a case study of cadmium and zinc competitive adsorption. Next, we further assessed the JAMM isotherm using another competitive adsorption case study of copper and chromium. Through extensive validation studies and error analysis, the JAMM isotherm was able to demonstrate its efficacy in predicting the adsorption behavior in several multicomponent adsorption systems accurately. The main advantage of JAMM isotherm over other multicomponent isotherms is that it utilizes and leverages the single-component adsorption parameters to simulate multicomponent isotherms. The proposed JAMM analytical isotherm model furthermore incorporates the interaction between the components, a mole fraction parameter, and a heterogeneity index, providing a more comprehensive modeling framework for multicomponent adsorption. The mole fraction term was introduced for the distribution of adsorption sites based on the relative number of molecules of each component. An additional term for interaction coefficient was introduced for the representation of interactions. During the validation of JAMM with three experimental case studies with negligible, small, and high competition systems of adsorbates, impressive predictions were exhibited, with the average normalized absolute percentage error as 6.05% and average R2 as 0.86, highlighting the model's robustness, versatility, and reliability. We propose that the new JAMM isotherm modeling framework might profoundly help in chemical engineering, environmental engineering, and materials science applications by providing a potent tool for analyzing and predicting multicomponent adsorption systems.
RESUMO
BACKGROUND: Western physicians tend to favour complete disclosure of a cancer diagnosis to the patient, while non-Western physicians tend to limit disclosure and include families in the process; the latter approach is prevalent in clinical oncology practice in India. Few studies, however, have examined patient preferences with respect to disclosure or the role of family members in the process. MATERIALS AND METHODS: Structured interviews were conducted with patients (N=127) in the medical oncology clinic of a tertiary referral hospital in Bangalore, India. RESULTS: Patients ranged in age from 18-88 (M=52) and were mostly male (59%). Most patients (72%) wanted disclosure of the diagnosis cancer, a preference significantly associated with higher education and English proficiency. A majority wanted their families to be involved in the process. Patients who had wanted and not wanted disclosure differed with respect to their preferences regarding the particulars of disclosure (timing, approach, individuals involved, role of family members). Almost all patients wanted more information concerning their condition, about immediate medical issues such as treatments or side effects, rather than long-term or non-medical issues. CONCLUSIONS: While most cancer patients wanted disclosure of their disease, a smaller group wished that their cancer diagnosis had not been disclosed to them. Regardless of this difference in desire for disclosure, both groups sought similar specific information regarding their cancer and largely favoured involvement of close family in decision making. Additional studies evaluating the influence of factors such as disease stage or family relationships could help guide physicians when breaking bad news.