Search

This study proposes an additional feature of optical coherence tomography (OCT) as a guidance system for laser surgery, aiming to enhance ablation efficiency during laser osteotomy. A long-range Bessel-like beam OCT system is integrated with an Er:YAG laser. The signal sensitivity of the OCT system is measured under various conditions encountered during laser osteotomy. The results demonstrate that the OCT sensitivity decreases from 87.53 dB to 79.54 dB and 68.93 dB in the presence of debris and water, respectively. These findings highlight the potential application signal sensitivity of OCT as a criterion for detecting the accumulation of water and debris, which could lead to a reduction in ablation efficiency during laser osteotomy using Er:YAG laser.

Graphene is a promising candidate for use as a cushioning/filler material in composites due to its extraordinary mechanical and thermal properties. When added to composite materials, graphene can improve the composite's overall strength, durability, and impact resistance. One of the primary benefits of using graphene as a cushioning/filler material in composite materials is its high strength-to-weight ratio. Graphene is one of the most robust materials known to man, and when added to composite materials, it can significantly increase their strength without adding much weight. Another benefit is its high thermal conductivity. Graphene can dissipate heat quickly and efficiently, which can be advantageous in applications where thermal management is critical, such as electronics and aerospace. The addition of graphene can reduce the amount of energy transferred during impact, reducing the risk of damage or failure of the composite material. In addition to its thermal and mechanical properties, graphene is highly chemically resistant, making it ideal for use in harsh environments. It is also relatively inexpensive compared to other high-performance materials, making it an attractive option for large-scale industrial applications. Overall, graphene has the potential to revolutionize the use of composite materials by providing a high-strength, lightweight, and thermally conductive cushioning/filler material that can improve the durability and performance of composite materials in a diverse range of applications. Various application in diverse field has been elaborated in this review work.

This study aimed to optimize the ablation depth and duration at a fixed energy using a Ho:YAG laser, considering fiber delivery applications. According to the measurements performed with an optical coherence tomography system, we obtained depths of about 1.4 mm with 500 mJ/pulse applied energy when moving the laser along a 1 cm line for 60 s (corresponding to ~50 pulses per position). Coupling this laser into a flexible fiber (θ= 250 μm) will be the next step for future minimal-invasive bone ablation trials. Furthermore, deeper ablation (~1.5 mm) was also achieved with different energy levels on bone samples.

This study investigated the impact of Problematic Internet Use (PIU) on Iranian adolescents' Psychological Well-Being (PWB), focusing on the mediating roles of sleep quality and self-regulation. Data was collected from a sample of students (n = 228, girl = 197, boy = 31) aged 12 to 19 years. Participants completed four online questionnaires, including the PIU questionnaire, the Psychological Well-Being Scale (PWBS), the Pittsburgh Sleep Quality Index (PSQI), and the Short Self-Regulation Questionnaire (SSRQ). Results confirmed that while PIU was not directly effective on PWB, it was indirectly effective through the mediation of sleep quality and self-regulation. By gaining such understanding, we can devise interventions to enhance individuals' sleep quality and self-regulatory capacities, thereby improving their PWB.

The environmental fate of non-steroidal anti-inflammatory drugs (NSAIDs) in the urban water cycle is still uncertain and their status is mainly assessed based on specific water components and information on human risk assessments. This study (a) explores the environmental fate of NSAIDs (ibuprofen, IBU; naproxen, NAP; ketoprofen, KET; diazepam, DIA; and diclofenac, DIC) in the urban water cycle, including wastewater, river, and treated water via gas chromatography-mass spectrophotometry (GCMS), (b) assesses the efficiency of reducing the targeted NSAIDs in sewage treatment plant (STP) using analysis of variance (ANOVA), and (c) evaluates the ecological risk assessment of these drugs in the urban water cycle via teratogenic index (TI) and risk quotient (RQ). The primary receptor of contaminants comes from urban areas, as a high concentration of NSAIDs is detected (ranging from 5.87 × 103 to 7.18 × 104 ng/L). The percentage of NSAIDs removal in STP ranged from 25.6% to 92.3%. The NAP and KET were still detected at trace levels in treated water, indicating the persistent presence in the water cycle. The TI values for NAP and DIA (influent and effluent) were more than 1, showing a risk of a teratogenic effect. The IBU, KET, and DIC had values of less than 1, indicating the risk of lethal embryo effects. The NAP and DIA can be classified as Human Pregnancy Category C (2.1 > TI ≥ 0.76). This work proved that these drugs exist in the current urban water cycle, which could induce adverse effects on humans and the environment (RQ in high and low-risk categories). Therefore, they should be minimized, if not eliminated, from the primary sources of the pollutant (i.e., STPs). These pollutants should be considered a priority to be monitored, given focus to, and listed in the guideline due to their persistent presence in the urban water cycle.

This article discusses the extent of the spread of contamination in water distribution networks which may enter through a pipe leak, and the decay rate of chlorine for a specified design duration. A comprehensive water quality analysis is performed using EPANet 2.2 for the spread of contamination and chlorine decay. The results show that a contaminant entering at the highest point of the network would pollute the whole network whereas the effect of such a contaminant would be limited if it enters at the lowest location. Also, the initial chlorine concentration is found to be more for such critical nodes which are higher in elevation, although the decay rate remains the same. The research proves to be beneficial for the management of water distribution through pipe networks against contaminants for maintaining public health.

This study strived to determine the effectiveness of integrative teaching of reading strategies and working memory on basic math and problem-solving skills. It is a quasi-experimental pretest-posttest study carried out on 50 second-graders from Chahashk Shandiz village in the academic year of 2020-2021 who were randomly selected by cluster sampling and randomly divided into experimental and control groups. The intervention was performed by cellphone software through virtual education in two steps. The experimental group underwent integrative training for 20 sessions, but the control group did not receive any intervention. Colored Progressive Matrices (1956) and a researcher-made story problem-solving and arithmetic skills test were used to collect data. Descriptive statistics (mean and standard deviation) and one-way multivariate analysis of covariance were used to analyze the data. The results showed that the integrative teaching of reading strategies and working memory enhanced the basic math skills, with an effect size of 0.67 in second-grade elementary students (P<0.001). According to the results, integrative teaching improved students' problem-solving skills but did not affect their skills in arithmetic operations. Therefore, second-grade elementary teachers can use this method to enhance their story problem-solving skills.

Refractory humic substances (HSs), which include humic and fulvic acid as well as hydrophilic portion, are the prime pollutants of stabilized landfill leachate with a concentrated color and chemical oxygen demand (COD). Spectroscopic and microscopic analysis of humic acid remaining in stabilized leachate as a pollutant contributor were conducted in this study. Microfiltration and centrifugation processes were applied to fractionate the humic acid from the HSs of stabilized leachate. The three-stage isolation process recovered a maximum of 1412 ± 2.5 mg/L (Pulau Burung leachate), 1510 ± 1.5 mg/L (Alor Pongsu leachate) at pH 1.5 and 1371 ± 2.5 mg/L (PBLS), and 1451 ± 1.5 mg/L (APLS) of humic acid (about 42% of the total COD concentration) at pH 2.5, which eventually indicates the efficiency of the process. The spectroscopic analysis of isolated humic acid through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) significantly indicates the existence of identical elements in the recovered humic acid. The subsequent reduction (around 37%, 36%, and 39%) in ultra-violet absorbance values (UV254, UV280), COD, and color in the humic acid isolated leachate indicates the acid’s significant contribution as a toxic pollutant through aromaticity and conjugated double-bond compounds.

Leachate generation is among the main challenging issues that landfill operators must handle. Leachate is created when decomposed materials and rainwater pass through the waste. Leachate carries many harmful pollutants, with high concentrations of BOD, COD, colour, heavy metals, ammoniacal nitrogen (NH3-N), and other organic and inorganic pollutants. Among them, COD, colour, and NH3-N are difficult to be completely eliminated, especially with a single treatment. They should be handled by appropriate treatment facilities before being safely released into the environment. Leachate remediation varies based on its properties, the costs of operation and capital expenditures, as well as the rules and regulations. Up until now, much scientific and engineering attention was given to the development of comprehensive solutions to leachate-related issues. The solutions normally demand a multi-stage treatment, commonly in the form of biological, chemical, and physical sequences. This review paper discussed the use of contemporary techniques to remediate landfill leachate with an emphasis on concentrated COD, colour, and NH3-N levels with low biodegradability that is normally present in old landfill or dumping grounds in developing countries. A semi-aerobic type of landfill design was also discussed, as this concept is potentially sustainable compared to others. Some of the challenges and future prospects were also recommended, especially for the case of Malaysia. This may represent landfills or dumpsites in other developing countries with the same characteristics.

Water shortage has been an issue for urbanized areas. For the Penang state in Malaysia, it is forecast that there will be a significant increase in water demand in the future. Penang authorities in Malaysia are trying to find an alternative water source to overcome the problem, with one of the options being the Perai River catchment. However, the river water quality was found to be polluted and not suitable to be used for water extraction for domestic consumption. This paper aims to study the pollution level variation due to changes in rainfall during the year in the Perai River Basin, and estimate the TMDL of the river in a particular case for BOD, COD, and NH3N parameters. A water quality model was developed for the Perai River, Jarak River and Kulim River using InfoWorks ICM. The year 2016 was selected as a model event due to data availability. BOD, COD and NH3N concentrations were used for TMDL calculation, and the load duration curve approach was used to estimate TMDL. The tidal effect at the downstream of the Perai River was found to impact the data analysis in the river stretch. It was found that pollutant load exceedance was the highest during the rainy season and the problematic pollutant was NH3N. Thus, local authorities need to focus on tidal and seasonal change factors when developing action plans to manage water quality issues in this basin.

This study conducts a preliminary investigation to determine the material properties of Cross- Laminated Timber (CLT) made from the bark of unproductive palm trunks. One-third of the lower part of palm trunks, aged over 20 years, was used for this purpose. CLTs were created by laminating palm boards into three and five layers, each measuring 200 mm x 20 mm x 1500 mm. A chemical epoxy was employed for lamination. The palm stems were dried in an oven at 110°C for 24 hours. Test results revealed a water content of 6.79% and a specific gravity of 0.23 gr/cm3 in oil palm stems. According to ASTM D143-94- 2005 and JIS Z210-21118 standards, wood's acceptable moisture content ranges from 12% to 20%. Given its low specific weight and minimal water content, palm oil trunks, including infill walls, show promise for use in earthquake-resistant construction.

Feedback systems have been utilized to reduce the possible thermal side effects of lasers for surgery by means of temperature monitoring to control irrigation systems. In this study, we investigated the potential application of optical coherence tomography as a means of detecting bone dehydration status. We investigated the penetration depth of the OCT laser and its respective relation to the hydration status of bone. A deep-learning method was utilized to differentiate between different levels of water content in bone tissue (fresh/hydrated, dehydrated, and carbonized) based on the OCT images. The proposed model achieved an accuracy of 0.912 on an independent test set, demonstrating its ability to accurately predict the state of the bone considering these three conditions. We believe this method can potentially accelerate the detection of dehydration during laser surgery, improving the safety of using lasers with real-time feedback.

Water is an essential natural compound on earth; all life forms on our planet need water to function properly [...]

Restaurant wastewater contains a high concentration of O&G, up to 3434 mg/L. This study aims to (a) assess the efficiency of EC combined with US methods for O&G removal in restaurant wastewater, (b) identify the optimum condition for COD degradation using EC treatment via response surface methodology (RSM), and (c) determine the morphological surface of the aluminium (Al) electrode before and after EC treatment. The wastewater samples were collected from the Lembaran cafeteria at the Universiti Sains Malaysia (USM). The efficiency of EC, US, and US-EC, combined methods for O&G removal, was investigated using a batch reactor (pH 7). The interelectrode distance (ID, 2–6 cm), electrolysis time (T, 15–35 min), and current density (CD, 40–80 A/m2) were analysed, followed by RSM. The response variables were O&G (1000 mg/L) and chemical oxygen demand (COD low range, 1000 mg/L). The central composite design (CCD) with a quadratic model was used to appraise the effects and interactions of these parameters. The morphological surface of the electrode used was observed via scanning electron microscopy (SEM). The optimum removal efficiencies obtained were 95.4% (O&G) and 75.9% (COD) (ID: 2.4 cm, T: 30.5 min, and CD: 53.2 A/m2). The regression line fitted the data (R2 O&G: 0.9838, and R2 COD: 0.9558). The SEM images revealed that the use of US was useful in minimising cavitation on the electrode surface, which could lower the EC treatment efficacy. The US-EC combined technique is highly recommended for O&G removal from the food industry’s wastewater.

In this study, the response surface methodology (RSM) and artificial neural network (ANN) were employed to study the adsorption process of 2,4-dichlorophenoxyacetic acid (2,4-D) by using modified hydrogel, i.e., activated carbon poly(dimethylaminoethyl methacrylate) (AC/PDMAEMA hydrogel). The effect of pH, the initial concentration of 2,4-D and the activated carbon content on the removal of 2,4-D and adsorption capacity were investigated through the face-centered composite design (FCCD), optimal design and two-level factorial design. The response surface plot suggested that higher removal of 2,4-D and adsorption capacity could be achieved at the higher initial concentration of 2,4-D and lower pH and activated carbon content. The modeling and optimization for the adsorption process of 2,4-D were also carried out by different design methods of RSM and different training methods of ANN. It was found that among the three design methods of RSM, the optimal design has the highest accuracy for the prediction of 2,4-D removal and adsorption capacity (R2 = 0.9958 and R2 = 0.9998, respectively). The numerical optimization of the optimal design found that the maximum removal of 2,4-D and adsorption capacity of 65.01% and 65.29 mg/g, respectively, were obtained at a pH of 3, initial concentration of 2,4-D of 94.52 mg/L and 2.5 wt% of activated carbon. Apart from the optimization of process parameters, the neural network architecture was also optimized by trial and error with different numbers of hidden neurons in the layers to obtain the best performance of the response. The optimization of the neural network was performed with different training methods. It was found that among the three training methods of the ANN model, the Bayesian Regularization method had the highest R2 and lowest mean square error (MSE) with the optimum network architecture of 3:9:2. The optimum condition obtained from RSM was also simulated with the optimized neural network architecture to validate the responses and adequacy of the RSM model.

Ensuring quality in healthcare calls for a coordinated, systematic, congruous, and sustained approach. Nevertheless, it demands defining what the quality of healthcare means in the local context. Presently, the Malaysian healthcare system utilizes various definitions of quality of healthcare across the different initiatives and levels of healthcare, which can lead to fragmented or ineffective quality improvement. The study aims to describe the process undertaken in developing an explicit definition of the quality of healthcare tailored to the Malaysian context, which is currently lacking. A pluralistic method was used to explore the different perspectives. Three distinct approaches were used to understand how quality is defined among the different stakeholder groups: (i) interactive policy-makers engagement sessions, (ii) a review of local quality-related documents, and (iii) an online survey engaging the public. The domains depicting quality of healthcare that emerged through these three approaches were mapped against a framework and synthesized to form the local definition of quality. A national quality-related technical working group convened on several sessions to achieve consensus and finalize the definition of quality of healthcare. Quality healthcare in Malaysia is defined as providing high-quality healthcare that is safe, timely, effective, equitable, efficient, people-centred, and accessible [STEEEPA] which is innovative and responsive to the needs of the people, and is delivered as a team, in a caring and professional manner in order to improve health outcomes and client experience. The consensus-driven local definition of healthcare quality will guide policies and ensure standardization in measuring quality, thereby steering efforts to improve the quality of healthcare services delivered in Malaysia.