Validation of key components in designing a social skills training content using virtual reality for high functioning autism youth-A Fuzzy Delphi method

The use of virtual reality in social skills training for high functioning autism spectrum disorder (HFASD) youth has been found to be engaging and enjoyable. Despite the promising results, previous literature indicates that there has been no consensus on the social skills target in the training content. There is also limited research on how evidence-based strategies like cognitive and behaviour techniques are instantiated into the VR environment to teach social skills. The aim of this study is to determine the key components to design a social skills training content using virtual reality for youths with HFASD. The Fuzzy Delphi method (FDM) was used to obtain expert consensus on social skills difficulties and cognitive behavioral techniques included in the content in three phases. In phase 1, a questionnaire was developed from in-depth interviews and scientific literature review. The in-depth interviews were conducted with 13 HFASD youth, 7 parents and 6 experts. In phase 2, 3 experts rated the relevance of the items in the questionnaire using an item-level content validity index (I-CVI) assessment. In phase 3, the questionnaire was distributed to 10 experts to rate their level of agreement on each component using a 7-point Likert scale. Components that received a value above 75%, threshold value (d) ≤ 0.2, fuzzy score (A) ≥ α - cut value = 0.5 and higher rank based on defuzzification score were prioritized to be included in the content. Items that received higher expert consensus on social skills difficulties included assessing non-verbal responses, initiating, maintaining, and leaving conversations, emotional difficulties and difficulties in perspective taking. Cognitive and behavioral techniques that received higher expert consensus were psychoeducation, modelling, relaxation techniques, reinforcements, and perspective-taking questions. These key components can be used as a framework for the development of virtual learning content for social skills training in future studies.

Micro energy harvesting for IoT platform: Review analysis toward future research opportunities

Micro-energy harvesting (MEH) is a technology of renewable power generation which is a key technology for hosting the future low-powered electronic devices for wireless sensor networks (WSNs) and, the Internet of Things (IoT). Recent technological advancements have given rise to several resources and technologies that are boosting particular facets of society. Many researchers are now interested in studying MEH systems for ultra-low power IoT sensors and WSNs. A comprehensive study of IoT will help to manage a single MEH as a power source for multiple WSNs. The popular database from Scopus was used in this study to perform a review analysis of the MEH system for ultra-low power IoT sensors. All relevant and important literature studies published in this field were statistically analysed using a review analysis method by VOSviewer software, and research gaps, challenges and recommendations of this field were investigated. The findings of the study indicate that there has been an increasing number of literature studies published on the subject of MEH systems for IoT platforms throughout time, particularly from 2013 to 2023. The results demonstrate that 67% of manuscripts highlight problem-solving, modelling and technical overview, simulation, experimental setup and prototype. In observation, 27% of papers are based on bibliometric analysis, systematic review, survey, review and based on case study, and 2% of conference manuscripts are based on modelling, simulation, and review analysis. The top-cited articles are published in 5 different countries and 9 publishers including IEEE 51%, Elsevier 16%, MDPI 10% and others. In addition, several MEH system-related problems and challenges are noted to identify current limitations and research gaps, including technical, modelling, economic, power quality, and environmental concerns. Also, the study offers guidelines and recommendations for the improvement of future MEH technology to increase its energy efficiency, topologies, design, operational performance, and capabilities. This study's detailed information, perceptive analysis, and critical argument are expected to improve MEH research's viable future.

An innovative probabilistic hesitant fuzzy set MCDM perspective for selecting flexible packaging bags after the prohibition on single-use plastics

The probabilistic hesitant elements (PHFEs) are a beneficial augmentation to the hesitant fuzzy element (HFE), which is intended to give decision-makers more flexibility in expressing their biases while using hesitant fuzzy information. To extrapolate a more accurate interpretation of the decision documentation, it is sufficient to standardize the organization of the elements in PHFEs without introducing fictional elements. Several processes for unifying and arranging components in PHFEs have been proposed so far, but most of them result in various disadvantages that are critically explored in this paper. The primary objective of this research is to recommend a PHFE unification procedure that avoids the deficiencies of operational practices while maintaining the inherent properties of PHFE probabilities. The prevailing study advances the hypothesis of permutation on PHFEs by suggesting a new sort of PHFS division and subtraction compared with the existing unification procedure. Eventually, the proposed PHFE-unification process will be used in this study, an innovative PHFEs based on the Weighted Aggregated Sum Product Assessment Method-Analytic Hierarchy Process (WASPAS-AHP) perspective for selecting flexible packaging bags after the prohibition on single-use plastics. As a result, we have included the PHFEs-WASPAS in our selection of the most effective fuzzy environment for bio-plastic bags. The ranking results for the suggested PHFEs-MCDM techniques surpassed the existing AHP methods in the research study by providing the best solution. Our solutions offer the best bio-plastic bag alternative strategy for mitigating environmental impacts.

The development of sustainable IoT E-waste management guideline for households

The introduction of new technology, such as the Internet of Things (IoT), entails a growth in digital devices, which could ultimately result in a high amount of electronic trash (e-waste) production if they are not appropriately managed. Apart from that, the regulation on possible "IoT E-waste" generation is yet to be regulated, probably due to the new development and implementation of IoT globally. Hence, this paper proposed a Sustainable IoT E-waste Management guideline for households. This guideline could assist government agencies and policymakers in their strategies, planning, development, and implementation of a sustainable household IoT e-waste management initiatives in Malaysia. This study is an exploratory study that adopts a qualitative case study research method. The guideline was developed based on the Integrated Sustainable Waste Management (ISWM) Model. This guideline contributes to Malaysia's sustainability agenda in reducing carbon emissions intensity towards 2030 by 45 percent.

Systematic Literature Review on Visual Analytics of Predictive Maintenance in the Manufacturing Industry

The widespread adoption of cyber-physical systems and other cutting-edge digital technology in manufacturing industry production facilities may motivate stakeholders to embrace the idea of Industry 4.0. Some industrial companies already have different sensors installed on their machines; however, without proper analysis, the data collected is not useful. This systematic review's main goal is to synthesize the existing evidence on the application of predictive maintenance (PdM) with visual aids and to identify the key knowledge gaps in areas including utilities, power generation, industry, and energy consumption. After a thorough search and evaluation for relevancy, 37 documents were identified. Moreover, we identified the visual analytics of PdM, including anomaly detection, planning/scheduling, exploratory data analysis (EDA), and explainable artificial intelligence (XAI). The findings revealed that anomaly detection was a major domain in PdM-related works. We conclude that most of the literature lacks depth in terms of an overall framework that combines data-driven and knowledge-driven techniques of PdM in the manufacturing industry. Some works that utilized both techniques indicated promising results, but there is insufficient research on involving maintenance personnel's feedback in the latter stage of PdM architecture. Thus, there are still pertinent issues that need to be investigated, and limitations that need to be overcome before PdM is deployed with minimal human involvement.

Integrated NIR-HE based SPOT-5 image enhancement method for features preservation and edge detection

Recently, many researchers have directed their attention to methods of predicting shorelines by the use of multispectral images. Thus, a simple and optimised method using image enhancements is proposed to improve the low contrast of the Satellite pour l'Observation de la Terre-5 (SPOT-5) images in the detection of shorelines. The near-infrared (NIR) channel is important in this study to ensure the contrast of the vegetated area and sea classification, due to the high reflectance of leaves in the near infrared wavelength region. This study used five scenes of interest to show the different results in shoreline detection. The results demonstrated that the proposed method performed in an enhanced manner as compared to current methods when dealing with the low contrast ratio of SPOT-5 images. As a result, by utilising the near-infrared histogram equalization (NIR-HE), the contrast of all datasets was efficiently restored, producing a higher efficiency in edge detection, and achieving higher overall accuracy. The improved filtering method showed significantly better shoreline detection results than the other filter methods. It was concluded that this method would be useful for detecting and monitoring the shoreline edge in Tanjung Piai.

Ontologies application in the sharing economy domain: a systematic review

Purpose

This systematic literature review (SLR) paper presents the overview and analysis of the existing ontologies application in the SE domain. It discusses the main challenges in terms of its ontologies development and highlights the key knowledge areas for subdomains in the SE domain that provides a direction to develop ontologies application for SE systematically. The SE is not as straightforward as the traditional economy. It transforms the existing economy ecosystem through peer-to-peer collaborations mediated by the technology. Hence, the complexity of the SE domain accentuates the need to make the SE domain knowledge more explicit.

Design/methodology/approach

For the review, the authors only focus on the journal articles published from 2010 to 2020 and mentioned ontology as a solution to overcome the issues specific for the SE domain. The initial identification process produced 3,326 papers from 10 different databases.

Findings

After applying the inclusion and exclusion criteria, a final set of 11 articles were then analyzed and classified. In SE, good ontology design and development is essential to manage digital platforms, deal with data heterogeneity and govern the interoperability of the SE systems. Yet the preference to build an application ontology, lack of perdurant design and minimal use of the existing standard for building SE common knowledge are deterring the ontology development in this domain. From this review, an anatomy of the SE key subdomain areas is visualized as a reference to further develop the domain ontology for the SE domain systematically.

Originality/value

With the arrival of the Fourth Industrial Revolution (4IR), the sharing economy (SE) has become one of the important domains whose impact has been explosive, and its domain knowledge is complex. Yet, a comprehensive overview and analysis of the ontology applications in the SE domain is not available or well presented to the research community.

An Overview of Ontologies in Virtual Reality-Based Training for Healthcare Domain

Virtual reality (VR) is one of the state-of-the-art technological applications in the healthcare domain. One major aspect of VR applications in this domain includes virtual reality-based training (VRT), which simplifies the complicated visualization process of diagnosis, treatment, disease analysis, and prevention. However, not much is known on how well the domain knowledge is shared and considered in the development of VRT applications. A pertinent mechanism, known as ontology, has acted as an enabler toward making the domain knowledge more explicit. Hence, this paper presents an overview to reveal the basic concepts and explores the extent to which ontologies are used in VRT development for medical education and training in the healthcare domain. From this overview, a base of knowledge for VRT development is proposed to initiate a comprehensive strategy in creating an effective ontology design for VRT applications in the healthcare domain.

Pertinent Knowledge Storage Processes for Central Repository Design in Domain of Interlocking Institutional Worlds

Designing a Central Repository (CR) for supporting the domain of Interlocking Institutional Worlds (IWs) requires a theory or model from Knowledge Storage Process (KSP) literature to govern the stakeholders' participation in the CR platform. However, current KSP theories or models have limited capabilities, so there are clear gaps in the context of designing a CR for the domain of IWs. Therefore, this paper suggests processes which include Identification, Standard, Service, and Maintain (ISSM) as a new KSP model to fill these gaps. To understand the stakeholders' participation, the authors use the case study of Flood Management (FM) to make sense of the proposed ISSM model. This gives us better understanding towards CR design using the KSP model.

Business process improvement methods in healthcare: a comparative study

PURPOSE

According to the literature concerned with this study, less than satisfactory outcomes have been achieved through implementing business process improvements methods (BPIMs) in industries, in general, and in healthcare, in particular. The existing methods used need to be enhanced in order to create more effective outcomes. There has also been a lack of studies documenting gaps or shortfalls in implementing BPIMs, to be presented to the BPI research community. Therefore, researchers of this paper have attempted to fill gaps between theory and practice. On the contrary, there is also a need to link practical outcomes in the healthcare domain with those of the BPI research community. The purpose of this paper is to review popular BPIMs, techniques and tools applied in the healthcare domain; it seeks to examine and highlight their significant roles, clarify their pros and cons, and find opportunities to enhance their impact on the achievement of more sustainable improvements in the healthcare domain.

DESIGN/METHODOLOGY/APPROACH

This study has been carried out by using a methodology combining an in-depth literature review with a comparison framework, which is called as the "Framework for Comparing Business Process Improvement Methods." The framework is composed of seven dimensions and has been adapted from four recognized, related frameworks. In addition to the in-depth review of related literature and the adapted comparison framework, researchers have conducted several interviews with healthcare BPI practitioners in different hospitals, to attain their opinions of BPI methods and tools used in their practices.

FINDINGS

The main results have indicated that significant improvements have been achieved by implementing BPIMs in the healthcare domain according to related literature. However, there were some shortfalls in the existing methods that need to be resolved. The most important of these has been the shortfall in representing and analyzing targeted domain knowledge during improvement phases. The tool currently used for representing the domain, specifically flowcharts, is very abstract and does not present the domain in a clear form. The flowchart tool also fails to clearly present the separation of concerns between business processes and the information systems processes that support a business in a given domain.

PRACTICAL IMPLICATIONS

The findings of this study can be useful for BPI practitioners and researchers, mainly within the healthcare domain. The findings can help these groups to understand BPIMs shortfalls and encourage them to consider how BPIMs can be potentially improved.

ORIGINALITY/VALUE

This researchers of this paper have proposed a comparison framework for highlighting popular BPIMs in the healthcare domain, along with their uses and shortfalls. In addition, they have conducted a deep literature review based on the practical results obtained from different healthcare institutions implementing unique BPIMs around the world. There has also been valuable interview feedback attained from BPI leaders of specific hospitals in Saudi Arabia. This combination is expected to contribute to knowledge of BPIMs from both theoretical and practical points of view.

Influence of Mg/CTAB ratio on the structural, physicochemical properties and catalytic activity of amorphous mesoporous magnesium silicate catalysts

This study investigated the physicochemical and catalytic properties of mesoporous magnesium silicate catalysts prepared at various Mg/CTAB ratios (0.25, 0.50, 0.75 and 1.00). The XPS analysis detected a mixture of enstatite and magnesium carbonate species when the Mg/CTAB ratio was 0.25, and 0.50. A mixture of forsterite and magnesium carbonate species were detected when the Mg/CTAB ratio was 0.75 whereas for the Mg/CTAB ratio of 1.00, enstatite and magnesium metasilicate species were detected. A catalyst with the Mg/CTAB ratio of 1.00 demonstrated the highest catalytic activity in the oxidation of styrene. The styrene conversion rate was 59.0%, with 69.2% styrene oxide (StO) selectivity. The H₂O₂ molecules were activated regio-specifically by the magnesium species to prevent rapid self-decomposition while promoting selective interaction with styrene. All the parameters that influence the styrene conversion and product selectivity were evaluated using analysis of variance (ANOVA) with Tukey's test. The ANOVA analysis showed that the reaction time (h), Mg/CTAB ratio, styrene/H₂O₂ ratio, catalyst loading (mg) and temperature (°C) affect styrene conversion and product selectivity (StO) significantly (p < 0.05). The oxidation of styrene was well fitted to the pseudo-first-order model. The activation energy, E_a of the catalysed styrene epoxidation reaction was calculated to be 27.7 kJmol⁻¹. The catalyst can be reused several times without any significant loss in its activity and selectivity. The results from this study will be useful in designing and developing low cost, high activity catalysts from alkaline earth metals.

Increasing the magnesium content in direct synthesis will lead to the formation of different magnesium active sites that increase the styrene oxide selectivity under the same reaction conditions.

The Determinants of Adoption of Cloud-Based ERP of Nigerian's SMES Manufacturing Sector Using Toe Framework and Doi Theory

Adoption factors relating to enterprise resource planning (ERP) have been studied quite extensively over the years. Most of the earlier studies on cloud ERP have focused only on technical and operational issues. A few studies have addressed the adoption of cloud ERP from the user's perspective, mostly assessing the effects of the innovation characteristics or the contextual factors. Very few studies to date have conducted a holistic evaluation of both the direct and indirect effects of the determinants on cloud ERP adoption in manufacturing SMEs. Therefore, this study aims to explore and gain an understanding of the determinants of adoption factors for cloud ERP and its relative advantage to small and medium enterprises (SME) organisations. The manufacturing SMEs in Nigeria are specifically targeted. This study also seeks to develop a research model that integrates the innovation characteristics and technology-organisation-environment (TOE) perspectives that underlie its adoption.

The mediating role of knowledge integration model for enterprise systems success

Purpose

The purpose of this paper is to empirically demonstrate how knowledge management, particularly knowledge integration (KI), acts as a mediator in enterprise systems (ES) post-implementation stage and how transactional and transformational leadership styles are impacted toward ES success.

Design/methodology/approach

Drawing on the insights of 508 valid respondents from various business backgrounds that used ES in Malaysia, structural equation modeling was employed and the path modeling approach was used to investigate the underlying relationships between variables. The mediating effects were tested using the bootstrapping procedures presented by Preacher and Hayes.

Findings

The results support the mediating effects of KI mechanisms and both leadership styles toward ES success. The analysis revealed the importance of KI in an organization, especially by the leaders who manage the complexity of the ES in the post-implementation stage.

Research limitations/implications

The study can be extended by analyzing other leadership styles in-detail.

Practical implications

This paper is useful for practitioners as it acts as a guide to conduct management practice for business managers.

Originality/value

The results demonstrate the importance of leaders’ adoption of KI mechanisms in various business domains. This study approach can be used to investigate which sub-items of the leadership styles are more likely to promote KI mechanisms.

Abstract P2-07-04: Molecular regulators of resistance and relapse in chemorefractory triple-negative breast cancers

Triple-Negative Breast Cancer (TNBC) accounts for approximately one-fifth of breast cancer incidence but disproportionately high mortality. Two-thirds of early-stage TNBCs are resistant to pre-surgical chemotherapy and highly prone to relapse within 3 years. Morever, no advanced therapies are indicated for patients with these cancers. We have embarked on a comprehensive genomic analysis of chemoresistant TNBC to gain an in-depth understanding of molecular entities driving chemoresistance and relapse. By collecting somatic mutation and copy number, RNA-sequencing, and outcome data in the context of a phase II post-neoadjuvant clinical trial, we have uncovered several molecular mechanisms behind these aggressive cancers. Through the analysis of matched pairs sampled before and after chemotherapy, we have discovered multiple means by which tumors are able to overcome the effects of chemotherapy including clonal evolution of high-level oncogene amplification, repression of the in situ immune system, and upregulation of the stem cell-related MEK-ERK and JAK-STAT pathways. Investigation into factors related to prognosis revealed important correlations between relapse and immune and JAK-STAT signaling. Finally, using a novel method of demarcating loss-of-function of p53, which we have termed graduated inactivation, we discovered additional associations between p53 loss and relapse, mortality, and MYC signalling.

Citation Format: Hancock BA, Chen Y-H, Solzak JP, Ahmad MN, Wedge DC, Brinza D, Scafe C, Veitch J, Gottimukkala R, Short W, Atale RV, Ivan M, Badve SS, Schneider BP, Miller KD, Radovich M. Molecular regulators of resistance and relapse in chemorefractory triple-negative breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-07-04.

Alpha-Glucosidase Enzyme Biosensor for the Electrochemical Measurement of Antidiabetic Potential of Medicinal Plants

A biosensor for measuring the antidiabetic potential of medicinal plants was developed by covalent immobilization of α-glucosidase (AG) enzyme onto amine-functionalized multi-walled carbon nanotubes (MWCNTs-NH2). The immobilized enzyme was entrapped in freeze-thawed polyvinyl alcohol (PVA) together with p-nitrophenyl-α-D-glucopyranoside (PNPG) on the screen-printed carbon electrode at low pH to prevent the premature reaction between PNPG and AG enzyme. The enzymatic reaction within the biosensor is inhibited by bioactive compounds in the medicinal plant extracts. The capability of medicinal plants to inhibit the AG enzyme on the electrode correlates to the potential of the medicinal plants to inhibit the production of glucose from the carbohydrate in the human body. Thus, the inhibition indicates the antidiabetic potential of the medicinal plants. The performance of the biosensor was evaluated to measure the antidiabetic potential of three medicinal plants such as Tebengau (Ehretis laevis), Cemumar (Micromelum pubescens), and Kedondong (Spondias dulcis) and acarbose (commercial antidiabetic drug) via cyclic voltammetry, amperometry, and spectrophotometry. The cyclic voltammetry (CV) response for the inhibition of the AG enzyme activity by Tebengau plant extracts showed a linear relation in the range from 0.423-8.29 μA, and the inhibition detection limit was 0.253 μA. The biosensor exhibited good sensitivity (0.422 μA/mg Tebengau plant extracts) and rapid response (22 s). The biosensor retains approximately 82.16 % of its initial activity even after 30 days of storage at 4 °C.

The mediating role of knowledge integration in effect of leadership styles on enterprise systems success

Purpose

– The purpose of this paper is to show empirically how knowledge management, particularly knowledge integration (KI), acts as a mediator between different leadership styles and Enterprise Systems (ES) success. It proposes a model of KI as a mediator between two leadership styles (the transformational and transactional leadership styles). The study also aims to expose the most relevant leadership styles to be practiced by leaders when managing the ES post-implementation stage.

Design/methodology/approach

– Valid data were collected from 263 survey respondents in Malaysian companies. The authors employed structural equation modelling and used the path modelling approach to investigate the underlying relationships between the variables. The authors then tested the mediating effects of KI by using the bootstrapping procedures proposed by Preacher and Hayes, which suits the path analysis method.

Findings

– The results provide empirical evidence on the relationships between the variables and on the role of KI mechanisms as a mediator between leadership styles and ES success, especially in the ES post-implementation phase. Both leadership styles have to be practiced by leaders while managing an ES.

Research limitations/implications

– Future research can investigate the role of KI mechanisms as moderators between both leadership styles. The study can also be expanded by looking in-depth at other leadership styles.

Practical implications

– This paper is useful for management researchers and as a guide to management practice for business managers.

Originality/value

– This paper proposes a model that examines the vitality of KI effect in ES post-implementation stage by different leadership styles. The results expose the importance of leaders’ adoption of KI mechanisms and call for manager attention to the importance of using the right leadership styles when managing ES.

A Study towards the Relation of Customer Relationship Management Customer Benefits and Customer Satisfaction

The purpose of this study is to investigate the efficacy of customer relationship management (CRM) benefits for customers in relation to customer satisfaction. A model has been developed and empirically tested through survey data collected from 150 customers of three Malaysian companies. The results indicate that the benefits of CRM for customers have had a significant positive effect on their satisfaction in marketing companies. Personalized service, responsiveness to customer's needs, customer segmentation, customization of marketing, multichannel integration, time-saving and improving customer knowledge are the benefits that we proposed would affect customer satisfaction in order to significantly improve marketing performance. Additionally, the results reveal that all the benefits found, with the exception of time-saving, enhanced customer satisfaction. This paper contributes to the existing literature by incorporating the benefits of CRM for customers and the relationships of these benefits with their satisfaction in the proposed model.

The adsorption of heavy metal by Bornean oil palm shell and its potential application as constructed wetland media

Oil palm shell, a waste from palm oil industry, was cleaned and utilized as adsorbent. Its particle size distribution gave the uniformity coefficient of approximately two indicating that it can be used as filter bed media for continuous operation without resting. Its measured pH(pzc) of 4.1 is below the common pH of constructed wetland water body suggesting positive adsorption for heavy metal. The effect of various parameters on its adsorption was studied via batch experiments. The adsorption of Cu(II) and Pb(II) ions by oil palm shell showed a slightly better fit with the Freundlich compared to Langmuir. Its monolayer adsorption capacities were found to be 1.756 and 3.390mg/g for Cu(II) and Pb(II), respectively. High correlation coefficient of over 0.99 given by the pseudo-second-order model suggests that the rate limiting factor may be chemisorption. These findings suggest its potential application as constructed wetland media for the removal of heavy metal.

Ontology-Based Knowledge Management for Enterprise Systems

Companies face the challenges of expanding their markets, improving products, services and processes, and exploiting intellectual capital in a dynamic network. Therefore, more companies are turning to an Enterprise System (ES). Knowledge management (KM) has also received considerable attention and is continuously gaining the interest of industry, enterprises, and academia. For ES, KM can provide support across the entire lifecycle, from selection and implementation to use. In addition, it is also recognised that an ontology is an appropriate methodology to accomplish a common consensus of communication, as well as to support a diversity of KM activities, such as knowledge repository, retrieval, sharing, and dissemination. This paper examines the role of ontology-based KM for ES (OKES) and investigates the possible integration of ontology-based KM and ES. The authors develop a taxonomy as a framework for understanding OKES research. In order to achieve the objective of this study, a systematic review of existing research was conducted. Based on a theoretical framework of the ES lifecycle, KM, KM for ES, ontology, and ontology-based KM, guided by the framework of study, a taxonomy for OKES is established.

Adsorption characteristics of reactive dyes in columns of activated carbon

Adsorption behaviour of reactive dyes in fixed-bed adsorber was evaluated in this work. The characteristics of mass transfer zone (MTZ), where adsorption in column occurs, were affected by carbon bed depth and influent dye concentration. The working lifetime (t(x)) of MTZ, the height of mass transfer zone (HMTZ), the rate of mass transfer zone (RMTZ), and the column capacity at exhaustion (q(column)) were estimated for the removal of remazol reactive yellow and remazol reactive black by carbon adsorber. The results showed that column capacity calculated at 90% of column exhaustion was lower than carbon capacity obtained from equilibrium studies. This indicated that the capacity of activated carbon was not fully utilized in the fixed-bed adsorber. The bed-depth service time model (BDST) was applied for analysis of reactive yellow adsorption in the column. The adsorption capacity of reactive yellow calculated at 50% breakthrough point (N(0)) was found to be 0.1 kg kg(-1) and this value is equivalent to about 14% of the available carbon capacity. The results of this study indicated the applicability of fixed-bed adsorber for removing remazol reactive yellow from solution.

Microcolumn studies of dye adsorption onto manganese oxides modified diatomite

The method described here cannot fully replace the analysis of large columns by small test columns (microcolumns). The procedure, however, is suitable for speeding up the determination of adsorption parameters of dye onto the adsorbent and for speeding up the initial screening of a large adsorbent collection that can be tedious if a several adsorbents and adsorption conditions must be tested. The performance of methylene blue (MB), a basic dye, Cibacron reactive black (RB) and Cibacron reactive yellow (RY) was predicted in this way and the influence of initial dye concentration and other adsorption conditions on the adsorption behaviour were demonstrated. On the basis of the experimental results, it can be concluded that the adsorption of RY onto manganese oxides modified diatomite (MOMD) exhibited a characteristic "S" shape and can be simulated effectively by the Thomas model. It is shown that the adsorption capacity increased as the initial dye concentration increased. The increase in the dye uptake capacity with the increase of the adsorbent mass in the column was due to the increase in the surface area of adsorbent, which provided more binding sites for the adsorption. It is shown that the use of high flow rates reduced the time that RY in the solution is in contact with the MOMD, thus allowing less time for adsorption to occur, leading to an early breakthrough of RY. A rapid decrease in the column adsorption capacity with an increase in particle size with an average 56% reduction in capacity resulting from an increase in the particle size from 106-250 microm to 250-500 microm. The experimental data correlated well with calculated data using the Thomas equation and the bed depth-service time (BDST) equation. Therefore, it might be concluded that the Thomas equation and the BDST equations can produce accurate predication for variation of dye concentration, mass of the adsorbent, flow rate and particle size. In general, the values of adsorption isotherm capacity obtained in a batch system show the maximum values and are considerably higher than those obtained in a fixed-bed.

Effect of OH and silanol groups in the removal of dyes from aqueous solution using diatomite

The removal of methylene blue, reactive black (C-NN), and reactive yellow (MI-2RN) from aqueous solution by calcined and raw diatomite at 980 degrees C was studied. These studies demonstrated the importance of the various functional groups on the mechanism of adsorption. The role of pore size distribution in the dye adsorption studies was also investigated. The adsorption isotherms were pH dependent. Henry and Freundlich adsorption isotherms were used to model the adsorption behavior and experimental results for all dyes used exhibited heterogeneous surface binding. The removal of the ionisable functional groups increased the pH(ZPC) value from 5.4 to 7.7, while FTIR, SEM and XRD analysis showed a remarkable decrease of the characteristic Si-OH peaks after calcinations at 980 degrees C. The removal of hydroxyl groups from the surface of diatomite lead to a decrease in the adsorption. It was evident from pH and infrared spectra results that mechanisms of methylene blue and reactive yellow adsorption differed from that of reactive black. Accordingly, adsorption on the external surface by n-pi interaction between the pi system of the RB and the electron lone pairs of the oxygen atoms of siloxane group and columbic attraction between the dye and the surface of calcined diatomite was proposed as a possible adsorption mechanism.

The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth

The feasibility of using diatomite for the removal of the problematic reactive dyes as well as basic dyes from textile wastewater was investigated. Methylene blue, Cibacron reactive black and reactive yellow dyes were considered. Physical characteristics of diatomite such as pHsolution, pHZPC, surface area, Fourier transform infrared, and scanning electron microscopy were investigated. The surface area of diatomite was found to be 27.80 m2g(-1) and the pHZPC occurred around pH of 5.4. The results indicated that the surface charge of diatomite decreased as the pH of the solution increased with the maximum methylene blue removal from aqueous solution occurring at basic pH of around (10-11). Adsorption isotherms of diatomite with methylene blue, hydrolysed reactive black and yellow dyes were constructed at different pH values, initial dye concentrations and particle sizes. The experimental results were fitted to the Langmuir, Freundlich, and Henry models. The study indicated that electrostatic interactions play an important role in the adsorption of dyes onto diatomite. A model of the adsorption mechanism of methylene blue onto diatomite is proposed.

Magnetization transfer imaging diagnosis of intracranial tuberculomas

Tuberculomas (TB) can mimic brain tumors and abscesses. We performed prospective magnetization transfer ratio (MTR) analysis on 60 patients with 52 intracranial TB, 13 pyogenic abscesses and 65 tumors to determine the efficacy of magnetization transfer (MT) imaging in the differential diagnosis of brain tumors and infection. The nonenhancing cores of TB had significantly higher (P=.026) MTR (0.14+/-0.29) than necrotic components of high-grade gliomas (-0.19+/-0.22). The MTR of cores of TB were also higher than those of the cystic areas of low-grade gliomas (-0.53+/-0.32), benign (-0.09+/-0.21) and malignant (-0.07+/-0.25) tumors, and abscesses (-0.03+/-0.13), but the differences were not significant because of the small number of tumors and abscesses. There was also no significant difference between the MTR of abscesses, malignant and benign tumors. Using the criteria of MTR of necrotic center > 0.14 (mean MTR of TB) for diagnosing TB, MTR <-0.03 (mean MTR of abscesses) for diagnosing tumors and MTR between these values for diagnosing abscesses, MTI had diagnostic sensitivity of 68.42%, specificity of 80.49%, and accuracy of 76.67%. The improved diagnostic accuracy of MRI with the addition of MTR analysis from 86.67% to 91.67% and from 85.71% to 87.50% for both radiologists respectively was not significant. MTR analysis helped us to differentiate solitary TB or abscess from low-grade glioma in five patients and to diagnose multiple TB, abscesses, and metastases in four.