Search results for: filling ratio

Authors: Kimberley K. Whyte-Jones

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Public participation may improve the quality of environmental management decisions. However, the quality of such a decision is strongly dependent on the quality of the process that leads to it. In order to ensure an effective and efficient process, key features of best practice in participation should be carefully observed; this would also combat disillusionment of citizens, decision-makers and practitioners. The overarching aim of this study is to determine what constitutes an effective public participation process relevant to the Newfoundland and Labrador, Canada context, and to discover whether the public participation process that led to the 2014-2024 Provincial Sustainable Forest Management Strategy (PSFMS) met best practices criteria. The research design uses an exploratory case study strategy to consider a specific participatory process in environmental decision-making in Newfoundland and Labrador. Data collection methods include formal semi-structured interviews and the review of secondary data sources. The results of this study will determine the validity of a specific public participation best practice framework. The findings will be useful for informing citizen participation processes in general and will deduce best practices in public participation in environmental management in the province. The study is, therefore, meaningful for guiding future policies and practices in the management of forest resources in the province of Newfoundland and Labrador, and will help in filling a noticeable gap in research compiling best practices for environmentally related public participation processes.

Keywords: best practices, environmental decision-making, forest management, public participation

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Authors: Hee-Chang Lim

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The study aims to understand the surface pressure distribution around the bodies such as the suction pressure in the leading edge on the top and side-face when the aspect ratio of bodies and the wind direction are changed, respectively. We carried out the wind tunnel measurement and numerical simulation around a series of rectangular bodies (40^d×80^w×80^h, 80^d×80^w×80^h, 160^d×80^w×80^h, 80^d×40^w×80^h and 80^d×160^w×80^h in mm³) placed in a deep turbulent boundary layer. Based on a modern numerical platform, the Navier-Stokes equation with the typical 2-equation (k-ε model) and the DES (Detached Eddy Simulation) turbulence model has been calculated, and they are both compared with the measurement data. Regarding the turbulence model, the DES model makes a better prediction comparing with the k-ε model, especially when calculating the separated turbulent flow around a bluff body with sharp edged corner. In order to observe the effect of wind direction on the pressure variation around the cube (e.g., 80^d×80^w×80^h in mm), it rotates at 0º, 10º, 20º, 30º, and 45º, which stands for the salient wind directions in the tunnel. The result shows that the surface pressure variation is highly dependent upon the approaching wind direction, especially on the top and the side-face of the cube. In addition, the transverse width has a substantial effect on the variation of surface pressure around the bodies, while the longitudinal length has little or no influence.

Keywords: rectangular bodies, wind direction, aspect ratio, surface pressure distribution, wind-tunnel measurement, k-ε model, DES model, CFD

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Authors: Yao Song, Danni Cheng, Jianjun Ren

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Objectives: We aimed to explore the prognostic effects of absolute values and dynamic changes of common hematological indices on oropharynx squamous cell carcinoma (OPSCC) patients treated with radiation. Methods and materials: The absolute values of white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), hemoglobin (Hb), platelet (Plt), albumin (Alb), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at baseline (within 45 days before radiation), 1-, 3-, 6- and 12-months after the start of radiotherapy were retrospectively collected. Locally-estimated smoothing scatterplots were used to describe the smooth trajectory of each index. A mixed-effect model with a random slope was fitted to describe the changing rate and trend of indices over time. Cox proportional hazard analysis was conducted to assess the correlation between hematological indices and treatment outcomes. Results: Of the enrolled 85 OPSCC patients, inflammatory indices, such as WBC and ALC, dropped rapidly during acute treatment and gradually recovered, while NLR and PLR increased at first three months and subsequently declined within 3-12 months. Higher absolute value or increasing trend of nutritional indices (Alb and Hb) was associated with better prognosis (all p<0.05). In contrast, patients with higher absolute value or upward trend of inflammatory indices (WBC, ANC, Plt, PLR and NLR) had worse survival (all p<0.05). Conclusions: The absolute values and dynamic changes of hematological indices were valuable prognostic factors for OPSCC patients who underwent radiotherapy.

Keywords: hematological indices, oropharyngeal cancer, radiotherapy, NLR, PLR

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Authors: Nadia A. Wassif, Bassem S. Nabawy

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This paper gives an account of the petrophysical characteristics and the petrographical descriptions of Tertiary vesicular and amygdaloidal olivine basalt samples from Wadi Wizr in the central Eastern Desert of Egypt. The petrographical studies indicated that the studied vesicular basalt is rich in calcic-plagioclase, augite and olivine in addition to numerous amounts of fine opaque minerals and vesicules filled with carbonate and quartz amygdales. The degree of oxidation and alteration of magnetite and ilmenite were discussed in details. Petrophysically, the studied samples can be grouped into two main groups; the first group of samples is amygdaloidal basalt as the second group is vesicular. The vesicular group (the permeable one) is characterized by fair to very good porosity ‘Φ’, good to very good permeability ‘k’, very low true formation factor ‘F’ and micro to ultra micropores. On the other hand, the amygdaloidal basalt group (impermeable group) is characterized by very low storage capacity properties, fair porosity, negligible permeability, medium to high true formation factor and ultra micorpores. It has been found that; the petrophysical behavior is strongly dependent on the degree of oxidation and alteration; and in particular on the rate of cooling and oxidation of the ore minerals which caused filling in the primarily produced vesicules by low temperature secondary minerals.

Keywords: vesicular, amygdaloidal, basalt, petrophysics, Egypt

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Authors: Ehsan Mohseni, Waiching Tang, Shanyong Wang

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Low thermal conductivity of phase change materials (PCMs) affects the thermal performance and energy storage efficiency of latent heat thermal energy storage systems. In the current research, a structural lightweight concrete with function of indoor temperature control was developed using thermal energy storage aggregates (TESA) and nano-titanium (NT). The macro-encapsulated technique was served to incorporate the PCM into the lightweight aggregate through vacuum impregnation. The compressive strength was measured, and the thermal performance of concrete panel was evaluated by using a self-designed environmental chamber. The impact of NT on microstructure was also assessed via scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) tests. The test results indicated that NT was able to increase the compressive strength by filling the micro pores and making the microstructure denser and more homogeneous. In addition, the environmental chamber experiment showed that introduction of NT into TESA improved the heat transfer of composites noticeably. The changes were illustrated by the reduction in peak temperatures in the centre, outside and inside surfaces of concrete panels by the inclusion of NT. It can be concluded that NT particles had the capability to decrease the energy consumption and obtain higher energy storage efficiency by the reduction of indoor temperature.

Keywords: heat transfer, macro-encapsulation, microstructure properties, nanoparticles, phase change material

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Authors: Bashar Tarawneh, Yasser Hakam

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Rapid Impact Compaction (RIC) is a modern dynamic compaction device mainly used to compact sandy soils, where silt and clay contents are low. The device uses the piling hammer technology to increase the bearing capacity of soils through controlled impacts. The RIC device uses "controlled impact compaction" of the ground using a 9-ton hammer dropped from the height between 0.3 m to 1.2 m onto a 1.5 m diameter steel patent foot. The delivered energy is about 26,487 to 105,948 Joules per drop. To evaluate the performance of this technique, three project sites in the United Arab Emirates were improved using RIC. In those sites, a loose to very loose fine to medium sand was encountered at a depth ranging from 1.0m to 4.0m below the ground level. To evaluate the performance of the RIC, Cone Penetration Tests (CPT) were carried out before and after improvement. Also, load tests were carried out post-RIC work to assess the settlements and bearing capacity. The soil was improved to a depth of about 5.0m below the ground level depending on the CPT friction ratio (the ratio between sleeve friction and tip resistance). CPT tip resistance was significantly increased post ground improvement work. Load tests showed enhancement in the soil bearing capacity and reduction in the potential settlements. This study demonstrates the successful application of the RIC for middle-deep improvement and compaction of the ground. Foundation design criteria were achieved in all site post-RIC work.

Keywords: compaction, RIC, ground improvement, CPT

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Authors: Vijay Reena Durai, Krithica Srinivasan

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Introduction: The two fundamental skills involved in the growth and wellbeing of any child can be categorized into visual motor and perceptual skills. Visual stress is a disorder which is characterized by visual discomfort, blurred vision, misspelling words, skipping lines, letters bunching together. There is a need to understand the deficits in perceptual skills among children with visual stress. Aim: To estimate the association between visual stress and visual perceptual skills Objective: To compare visual perceptual skills of children with and without visual stress Methodology: Children between 8 to 15 years of age participated in this cross-sectional study. All children with monocular visual acuity better than or equal to 6/6 were included. Visual perceptual skills were measured using test for visual perceptual skills (TVPS) tool. Reading speed was measured with the chosen colored overlay using Wilkins reading chart and pattern glare score was estimated using a 3cpd gratings. Visual stress was defined as change in reading speed of greater than or equal to 10% and a pattern glare score of greater than or equal to 4. Results: 252 children participated in this study and the male: female ratio of 3:2. Majority of the children preferred Magenta (28%) and Yellow (25%) colored overlay for reading. There was a significant difference between the two groups (MD=1.24±0.6) (p<0.04, 95% CI 0.01-2.43) only in the sequential memory skills. The prevalence of visual stress in this group was found to be 31% (n=78). Binary logistic regression showed that odds ratio of having poor visual perceptual skills was OR: 2.85 (95% CI 1.08-7.49) among children with visual stress. Conclusion: Children with visual stress are found to have three times poorer visual perceptual skills than children without visual stress.

Keywords: visual stress, visual perceptual skills, colored overlay, pattern glare

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Authors: S. Abd Rahim, F. A. Rahman, E. M. Nasir, N. A. Ramle

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Co-crystal is believed to improve the solubility and dissolution rates and thus, enhanced the bioavailability of poor water soluble drugs particularly during the oral route of administration. With the existing of poorly soluble drugs in pharmaceutical industry, the screening of co-crystal formation using carbamazepine (CBZ) as a model drug compound with dicarboxylic acids co-crystal formers (CCF) namely fumaric (FA) and succinic (SA) acids in ethanol has been studied. The co-crystal formations were studied by varying the mol ratio values of CCF to CBZ to access the effect of CCF concentration on the formation of the co-crystal. Solvent evaporation, slurry, and cooling crystallisations which representing the solution based method co-crystal screening were used. The product crystal from the screening was characterized using X-ray powder diffraction (XRPD). The XRPD pattern profile analysis has shown that the CBZ co-crystals with FA and SA were successfully formed for all ratios studied. The findings revealed that CBZ-FA co-crystal were formed in two different polymorphs. It was found that CBZ-FA form A and form B were formed from evaporation and slurry crystallisation methods respectively. On the other hand, in cooling crystallisation method, CBZ-FA form A was formed at lower mol ratio of CCF to CBZ and vice versa. This study disclosed that different methods and mol ratios during the co-crystal screening can affect the outcome of co-crystal produced such as polymorphic forms of co-crystal and thereof. Thus, it was suggested that careful attentions is needed during the screening since the co-crystal formation is currently one of the promising approach to be considered in research and development for pharmaceutical industry to improve the poorly soluble drugs.

Keywords: co-crystal, dicarboxylic acid, carbamazepine, industry

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Authors: Swati Srivastava, Ashish Kumar Upadhyay

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Haemophilus influenzae Type B (Hib) cause infections of pneumonia, meningitis, epiglottises and other invasive disease exclusively among children under age five. Occurrence of these infections may impair child growth by causing micronutrient deficiency. Using longitudinal data from first and second waves of Young Lives Study conducted in India during 2002 and 2006-07 respectively and multivariable logistic regression models (using generalised estimation equation to take into account the cluster nature of sample), this study aims to examine the impact of Hib vaccination on child anthropometric outcomes (stunting, underweight and wasting) in India. Bivariate result shows that, a higher percent of children were stunted and underweight among those who were not vaccinated against Hib (39% & 48% respectively) as compare to those who were vaccinated (31% and 39% respectively).The risk of childhood stunting and underweight was significantly lower among children who were vaccinated against Hib (odds ratio: 0.77, 95% CI: 0.62-0.96 and odds ratio: 0.79, 95% C.I: 0.64-0.98 respectively) as compare to the unvaccinated children. No significant association was found between vaccination status against Hib and childhood wasting. Moreover, in the statistical models, about 13% of stunting and 12% of underweight could be attributable to lack of vaccination against Hib in India. Study concludes that vaccination against Hib- in addition to being a major intervention for reducing childhood infectious disease and mortality- can be consider as a potential tool for reducing the burden of undernutrition in India. Therefore, the Government of India must include the vaccine against Hib into the Universal Immunization Programme in India.

Keywords: Haemophilus influenzae Type-B, Stunting, Underweight, Wasting, Young Lives Study (YLS), India

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Authors: Shinji Sato, M. M. A. Alam, Manabu Takao

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In recent, investigation of an unsteady flow inside the resonance tube have become a strongly motivated research field for their potential application as high-frequency actuators. By generating a shock wave inside the resonance tube, a high temperature and pressure can be achieved inside the tube, and this high temperature can also be used to ignite a jet engine. In the present research, a computational fluid dynamics (CFD) analysis was carried out to investigate the flow inside the resonance tube. The density-based solver of rhoCentralFoam in OpenFOAM was used to numerically simulate the flow. The supersonic jet that was driven by a cylindrical nozzle with a nominal exit diameter of φd = 20.3 mm impinged onto the resonance tube. The jet pressure ratio was varied between 2.6 and 7.8. The gap s between the nozzle exit and tube entrance was changed between 1.5d and 3.0d. The diameter and length of the tube were taken as D = 1.25d and L=3.0D, respectively. As a result, when a supersonic jet has impinged onto the resonance tube, a compression wave was found generating inside the tube and propagating towards the tube end wall. This wave train resulted in a rise in the end wall gas temperature and pressure. While, in an outflow phase, the gas near tube enwall was found cooling back isentropically to its initial temperature. Thus, the compression waves repeated a reciprocating motion in the tube like a piston, and a fluctuation in the end wall pressures and temperatures were observed. A significant change was found in the end wall pressures and temperatures with a change of jet flow conditions. In this study, the highest temperature was confirmed at a jet pressure ratio of 4.2 and a gap of s=2.0d

Keywords: compressible flow, OpenFOAM, oscillations, a resonance tube, shockwave

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Authors: Medya Fathi

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Moving toward sustainable development is among today’s critical issues worldwide that make all industries, particularly construction, pay increasing attention to a healthy environment and a society with a prosperous economy. One of the solutions is to improve buildings’ energy performance by cutting energy consumption and related carbon emissions, eventually improving the quality of life. Unfortunately, the energy demand for buildings is rising. For instance, in Europe, the building sector accounts for 19% of the global energy-related greenhouse gas (GHGs) emissions, the main contributor to global warming in the last 50 years, and 36% of the total CO2 emissions, according to European Commission 2019. The crisis of energy use demands expanding knowledge and understanding of the potential benefits of energy-efficient buildings. In this regard, the present paper aims to critically review the existing body of knowledge on improving energy efficiency in buildings and detail the significant research contributions. Peer-reviewed journal articles published in the last decade in reputed journals were reviewed using the database Scopus and keywords of Sustainability, Sustainable Development, Energy Performance, Energy Consumption, Energy Efficiency, and Buildings. All contributions will be classified by journal type, publication time, country/region, building occupancy type, applied strategies, and findings. This study will provide an essential basis for researchers working on missing areas and filling the existing gaps in the body of knowledge.

Keywords: sustainability, energy performance, energy efficiency, buildings, review

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Authors: Tzu-Jung Tseng, Pei-Hsuen Han, Tsung-Hsueh Lu

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Background: Choropleth mortality map is commonly used to identify areas with higher mortality risk. However, the use of choropleth map alone might result in the misinterpretation of differences in mortality rates between areas. Two areas with different color shades might not actually have a significant difference in mortality rates. The mortality rates estimated for an area with a small population would be less stable. We suggest of bringing the 95% confidence intervals (CI) into the choropleth mortality map to help users interpret the areal mortality rate difference more properly. Method: In the first choropleth mortality map, we used only three color to indicate standardized mortality ratio (SMR) for each district in Tainan, Taiwan. The red color denotes that the SMR of that district was significantly higher than the Tainan average; on the contrary, the green color suggests that the SMR of that district was significantly lower than the Tainan average. The yellow color indicates that the SMR of that district was not statistically significantly different from the Tainan average. In the second choropleth mortality map, we used traditional sequential color scheme (color ramp) for different SMR in 37 districts in Tainan City with bar chart of each SMR with 95% CI in which the users could examine if the line of 95% CI of SMR of two districts overlapped (nonsignificant difference). Results: The all-causes SMR of each district in Tainan for 2008 to 2013 ranged from 0.77 (95% CI 0.75 to 0.80) in East District to 1.39 Beimen (95% CI 1.25 to 1.52). In the first choropleth mortality map, only 16 of 37 districts had red color and 8 districts had green color. For different causes of death, the number of districts with red color differed. In the first choropleth mortality map we added a bar chart with line of 95% CI of SMR in each district, in which the users could visualize the SMR differences between districts. Conclusion: Through the use of 95% CI the users could interpret the aral mortality differences more properly.

Keywords: choropleth map, small area variation, standardized mortality ratio (SMR), Taiwan

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Authors: Kerem Can Dizdar, Semih Ateş, Ozan Güler, Gökhan Basman, Derya Dışpınar, Cevat Fahir Arısoy

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Grain refinement and obtaining homogeneous microstructure is the key parameter in casting of aluminum alloys. Ti has been traditionally used as grain refiner, however, inconsistency and heterogeneous dendrite arms, as well as fading efficiency, have been the drawbacks of Ti. Alternatively, Nb (Niobium) has gained attention. In this work, the effect of Nb was investigated in case of both as cast and T6 heat treated conditions. Different ratios of Nb (0.0, 0.03, 0.05, 0.07, 0.1 weight%) were added to AlSi11 alloy, mechanical properties were examined statistically, and relationship was established between microstructure and mechanical properties by examining the grain size and dendrite characteristics before and after heat treatment. Results indicate that in the case of as cast state; with the increasing addition of Nb has no significant effect on yield strength, however, it increases the tensile strength and elongation starting with 0.05wt% ratio, and it remains constant up to 0.1wt%. For the heat-treated condition; Nb addition provides increment at yield strength and tensile strength up to 0.05wt%, but it leads to decrementfrom 0.05 to 0.1wt%. The opposite is valid for the elongation; It decreases in between 0-0.05wt% then rises in range of 0.05-0.1wt%. Highest yield strength and ultimate tensile strength were found T6 heat treated 0.05wt% Nb addition. 0.05wt% was found as critical Nbaddition ratio for mechanical properties of Al-11Si alloys. Grain refinement and obtaining homogeneous microstructure is the key parameter in casting of aluminum alloys. Ti has been traditionally used as grain refiner, however, inconsistency and heterogeneous dendrite arms, as well as fading efficiency, have been the drawbacks of Ti. Alternatively, Nb (Niobium) has gained attention. In this work, the effect of Nb was investigated in case of both as cast and T6 heat treated conditions. Different ratios of Nb (0.0, 0.03, 0.05, 0.07, 0.1 weight%) were added to AlSi11 alloy, mechanical properties were examined statistically, and relationship was established between microstructure and mechanical properties by examining the grain size and dendrite characteristics before and after heat treatment. Results indicate that in the case of as cast state; with the increasing addition of Nb has no significant effect on yield strength, however, it increases the tensile strength and elongation starting with 0.05wt% ratio, and it remains constant up to 0.1wt%. For the heat-treated condition; Nb addition provides increment at yield strength and tensile strength up to 0.05wt%, but it leads to decrement from 0.05 to 0.1wt%. The opposite is valid for the elongation; It decreases in between 0-0.05wt% then rises in range of 0.05-0.1wt%. Highest yield strength and ultimate tensile strength were found T6 heat treated 0.05wt% Nb addition. 0.05wt% was found as critical Nbaddition ratio for mechanical properties of Al-11Si alloys.

Keywords: al-si alloy, grain refinement, heat treatment, mechanical properties, microstructure, niobium, sand casting

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Authors: Mohamed Abdullahi Gure, Farhia Ali Abdi

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There is almost a complete certainty among educators that parental involvement is the remedy for many of the problems facing schools. It is also widely acknowledged that school administrators and teachers have important roles in promoting parental involvement in children’s education. This work aims at examining the views of parents and teachers on school-partnership practices for promoting parental involvement in education in selected primary schools in Mogadishu-Somalia. The method, which has been employed in this study, is a mixed-method approach; data were collected from parents as well as from teachers of the selected schools using survey questionnaires and interviews. A sample size of 377 parents and 214 teachers participated in this study. This study used an instrument that has been developed by Epstein and Salinas (1993) to assess the perceptions of parents and teachers about parental involvement. Furthermore, data was collected qualitatively through interviews with parents and teachers of the selected schools. The findings of this study show that parents and teachers had similar positive perceptions towards school practices for parental involvement. This study is significant for several reasons. It contributes to the limited information on parental involvement in Somalia and therefore, filling a gap in the existing empirical literature. It offers information to educators as well as to parents, which will help them understand the issues that relate to parental involvement in education. It is hoped that information from this study will facilitate parents and teachers to understand each other’s ideas on parental involvement and develop positive working relations to support children to become successful in their education.

Keywords: Mogadishu, parents, school-partnership, practices, teachers

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Authors: Vu H. N. Khue, Marian Pavelka, Georg Jocher, Jiří Dušek, Le T. Son, Bui T. An, Ho Q. Bang, Pham Q. Huong

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Agriculture is an important economic sector of Vietnam, the most popular of which is wet rice cultivation. These activities are also known as the main contributor to the national greenhouse gas. In order to understand more about greenhouse gas exchange in these activities and to investigate the factors influencing carbon cycling and sequestration in these types of ecosystems, since 2019, the first eddy covariance station has been installed in a paddy field in Long An province, Mekong Delta. The station was equipped with state-of-the-art equipment for CO₂ and CH₄ gas exchange and micrometeorology measurements. In this study, data from the station was processed following the ICOS recommendations (Integrated Carbon Observation System) standards for CO₂, while CH₄ was manually processed and gap-filled using a random forest model from methane-gapfill-ml, a machine learning package, as there is no standard method for CH₄ flux gap-filling yet. Finally, the carbon equivalent (Ce) balance based on CO₂ and CH₄ fluxes was estimated. The results show that in 2020, even though a new water management practice - alternate wetting and drying - was applied to reduce methane emissions, the paddy field released 928 g Cₑ.m⁻².yr⁻¹, and in 2021, it was reduced to 707 g Cₑ.m⁻².yr⁻¹. On a provincial level, rice cultivation activities in Long An, with a total area of 498,293 ha, released 4.6 million tons of Cₑ in 2020 and 3.5 million tons of Cₑ in 2021.

Keywords: eddy covariance, greenhouse gas, methane, rice cultivation, Mekong Delta

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Authors: Wiem Daoud Ben Amor, Luis Martínez López, Hela Moalla Frikha

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Most of the multi-criteria group decision making (MCGDM) problems dealing with qualitative criteria require consideration of the large background of expert information. It is common that experts have different degrees of knowledge for giving their alternative assessments according to criteria. So, it seems logical that they use different evaluation scales to express their judgment, i.e., multi granular linguistic scales. In this context, we propose the extension of the classical additive ratio assessment (ARAS) method to the case of a hierarchical linguistics term for managing multi granular linguistic scales in uncertain contexts where uncertainty is modeled by means in linguistic information. The proposed approach is called the extended hierarchical linguistics-ARAS method (ARAS-ELH). Within the ARAS-ELH approach, the DM can diagnose the results (the ranking of the alternatives) in a decomposed style, i.e., not only at one level of the hierarchy but also at the intermediate ones. Also, the developed approach allows a feedback transformation i.e the collective final results of all experts able to be transformed at any level of the extended linguistic hierarchy that each expert has previously used. Therefore, the ARAS-ELH technique makes it easier for decision-makers to understand the results. Finally, An MCGDM case study is given to illustrate the proposed approach.

Keywords: additive ratio assessment, extended hierarchical linguistic, multi-criteria group decision making problems, multi granular linguistic contexts

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Authors: Shuwen Hu, Yuancheng Lou, Dongxu Ji

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Photovoltaic (PV) power generation, as one of the most commercialized methods to utilize solar power, can only convert a limited range of solar spectrum into electricity, whereas the majority of the solar energy is dissipated as heat. To address this problem, thermoelectric (TE) module is often integrated with the concentrated PV module for waste heat recovery and regeneration. In this research, a feasibility analysis is conducted for the tandem concentrated photovoltaic-thermoelectric (CPV-TE) hybrid system considering various operational parameters as well as TE material properties. Furthermore, the power output density of the CPV-TE hybrid system is maximized by selecting the optimal TE material with application of a systematic assessment methodology. In the feasibility analysis, CPV-TE is found to be more advantageous than sole CPV system except under high optical concentration ratio with low cold side convective coefficient. It is also shown that the effects of the TE material properties, including Seebeck coefficient, thermal conductivity, and electrical resistivity, on the feasibility of CPV-TE are interacted with each other and might have opposite effect on the system performance under different operational conditions. In addition, the optimal TE material selected by the proposed assessment methodology can improve the system power output density by 227 W/m2 under highly concentrated solar irradiance hence broaden the feasible range of CPV-TE considering optical concentration ratio.

Keywords: feasibility analysis, material assessment methodology, photovoltaic waste heat recovery, tandem photovoltaic-thermoelectric

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Authors: Chuchai Sujivorakul

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This research focused on the study of various parameters of fiber itself affecting on the flexure of hooked steel fiber reinforced concrete (HSFRC). The size of HSFRC beams was 150x150 mm in cross section and 550 mm in length, and the flexural test was carried out in accordance with EN-14651 standard. The test result was the relationship between centre-point load and crack-mount opening displacement (CMOD) at the centre notch. Controlled concrete had a compressive strength of 42 MPa. The investigated variables related to the hooked fiber itself were: (a) 3 levels of aspect ratio of fibers (65, 80 and 100); (b) 2 different fiber lengths (35 mm and 60 mm); (c) 2 different tensile strength of fibers (1100 MPa and 1500 MPa); and (d) 3 different fiber-end geometries (3D 4D and 5D fibers). The 3D hooked fibers have two plastic hinges at both ends, while the 4D and 5D hooked fibers are the newly developed steel fibers by Bekaert, and they have three and four plastic hinges at both ends, respectively. The hooked steel fibers were used in concrete with three different fiber contents, i.e., 20 30 and 40 kg/m³. From the study, it was found that all variables did not seem to affect the flexural strength at limit of proportionality (LOP) of HSFRC. However, they affected the residual flexural tensile strength (fR,j). It was observed that an increase in fiber lengths and the tensile strength the fibers would significantly increase in the fR,j of HSFRC, while the aspect ratio of the fiber would slightly effect the fR,j of HSFRC. Moreover, it was found that using 5D fibers would better enhance the fR,j and flexural behavior of HSFRC than 3D and 4D fibers, because they gave highest mechanical anchorage effect created by their hooked-end geometry.

Keywords: hooked steel fibers, fiber reinforced concrete, EN-14651, flexural test

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Authors: Juan A. Ferriz-Papi, Simon Thomas

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The construction industry generates large amounts of waste, usually mixed, which can be composed of different origin materials, most of them catalogued as non-hazardous. The European Union targets for this waste for 2020 have been already achieved by the UK, but it is mainly developed in downcycling processes (backfilling) whereas upcycling (such as recycle in new concrete batches) still keeps at a low percentage. The aim of this paper is to explore further in the use of recycled aggregates from construction and demolition waste (CDW) in concrete mixes so as to improve upcycling. A review of most recent research and legislation applied in the UK is developed regarding the production of concrete blocks. As a case study, initial tests were developed with a CDW recycled aggregate sample from a CDW plant in Swansea. Composition by visual inspection and sieving tests of two samples were developed and compared to original aggregates. More than 70% was formed by soil waste from excavation, and the rest was a mix of waste from mortar, concrete, and ceramics with small traces of plaster, glass and organic matter. Two concrete mixes were made with 80% replacement of recycled aggregates and different water/cement ratio. Tests were carried out for slump, absorption, density and compression strength. The results were compared to a reference sample and showed a substantial reduction of quality in both mixes. Despite that, the discussion brings to identify different aspects to solve, such as heterogeneity or composition, and analyze them for the successful use of these recycled aggregates in the production of concrete blocks. The conclusions obtained can help increase upcycling processes ratio with mixed CDW as recycled aggregates in concrete mixes.

Keywords: aggregates, concrete, concrete block, construction and demolition waste, recycling

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Authors: Asep Sukohar, Ramadhan Triyandi, Muhammad Iqbal, Sahidin, Suharyani

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Introduction: Resveratrol is a class of bioactive chemicals found in melinjo, which has a wide range of biological actions. The purpose of this study is to determine the linarin content of the melinjo fraksi by using preparative-high-performance liquid chromatography (prep-HPLC). Method: Extraction used the soxhletation method with 96% ethanol solvent. Fractionation used ethyl acetate and ethanol in a ratio of 1:1. Tracing of linarin compound used prep-HPLC with a mobile phase ratio of distilled water: methanol (55: 45, v/v). The presence of linarin was detected using a wavelength of 215 nm. Fourier Transform Infrared (FTIR) was used to identify the functional groups of compound. Result: The retention time required to elute the ethyl acetate fraction was 2.601 minutes. Compound separation identification using Fourier Transform Infrared Spectroscopy - Quest Attenuated Total Reflectance (FTIR - QATR) has a similarity value range with standards from 0 to 1000. The elution results of the ethyl acetate fraction have similar values with the standard compounds linarin (668), resveratrol (578), and catechin (455). Conclusion: Tracing for active compound in the ethyl acetate fraction of Gnetum Gnemon L. using prep-HPLC showed a strong suspicion of the presence of linarin compound.

Keywords: Gnetum gnemon L., linarin, prep-HPLC, fraction ethyl acetate

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Authors: F. O. Oboite, P. G. Comeau

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Advance regeneration is present in many lodgepole pine stands in Alberta. When the overstory pine canopy is killed by Mountain Pine Beetle (MPB) the growth of this advance is likely to increase. Understanding the growth response of these understory tree species is needed to improve mid-term timber supply projections and management decisions. To quantify the growth (diameter, height, height/diameter ratio) responses of black spruce and white spruce to lodgepole pine mortality, sample trees of black and white spruce advance regeneration were selected from 7 lodgepole pine dominated stands (5 attacked; 2 control) in the Foothills Region of western Alberta. Measurements were collected 7-8 years after MPB attack across a wide range of spruce height and stand densities. Analysis was done using mixed model linear regression. Result indicates that there was an increase in both diameter and height growth after MPB attack; however, this increase in growth was delayed for about four years. Both spruce species had similar height response and their height/diameter ratio decreased after release, partly as a result of increased understory light associated with loss of needles in the pine canopy. In addition, the diameter and height growth responses of both spruce species were strongly related to density, prerelease growth and initial size.

Keywords: mountain pine beetle, forest regeneration, lodgepole pine, growth response

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Authors: Ayan Giri, Lukaranjan Phukan, Shantanu Karmakar

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Structure and tectonics play a vital role in ore genesis and deposition. The existence of a swelling structure below the current level of a mine leads to the discovery of ores below some permeant developments of the mine. The discovery and the extraction of the ore body are very critical to sustain the business requirement of the mine. The challenge was to extract the ore without hampering the global stability of the mine. In order to do so, different mining options were considered and analysed by numerical modelling in FLAC3d software. The constitutive model prepared for this simulation is the improved unified constitutive model, which can better and more accurately predict the stress-strain relationships in a continuum model. The IUCM employs the Hoek-Brown criterion to determine the instantaneous Mohr-Coulomb parameters cohesion (c) and friction (ɸ) at each level of confining stress. The extra swelled part can be dimensioned as north-south strike width 50m, east-west strike width 50m. On the north side, already a stope (P1) is excavated of the dimension of 25m NS width. The different options considered were (a) Open stoping of extraction of southern part (P0) of 50m to the full extent, (b) Extraction of the southern part of 25m, then filling of both the primaries and extraction of secondary (S0) 25m in between. (c) Extraction of the southern part (P0) completely, preceded by backfill and modify the design of the secondary (S0) for the overall stability of the permanent excavation above the stoping.

Keywords: extraction, IUCM, FLAC 3D, stoping, tectonics

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Authors: Shima Behkami, Nor Shahirul Umirah Idris, Sharifuddin Md. Zain, Kah Hin Low, Mehrdad Gholami, Nima A. Behkami, Ahmad Firdaus Kamaruddin

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In this work, Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Isotopic Ratio Mass Spectrometry (IRMS) and Ultrasound Milko Tester were used to study milk samples obtained from various geographical locations in Malaysia. ICP-MS was used to determine the concentration of trace elements in milk, water and soil samples obtained from seven dairy farms at different geographical locations in peninsular Malaysia. IRMS was used to analyze the milk samples for isotopic ratios of δ13C, 15N and 18O. Nutritional parameters in the milk samples were determined using an ultrasound milko tester. Data obtained from these measurements were evaluated by Principal Component Analysis (PCA) and Hierarchical Analysis (HA) as a preliminary step in determining geographical origin of these milk samples. It is observed that the isotopic ratios and a number of the nutritional parameters are responsible for the discrimination of the samples. It was also observed that it is possible to determine the geographical origin of these milk samples solely by the isotopic ratios of δ13C, 15N and 18O. The accuracy of the geographical discrimination is demonstrated when several milk samples from a milk factory taken from one of the regions under study were appropriately assigned to the correct PCA cluster.

Keywords: inductively coupled plasma mass spectroscopy ICP-MS, isotope ratio mass spectroscopy IRMS, ultrasound, principal component analysis, hierarchical analysis, geographical origin, milk

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Authors: Branimir Jurun, Elza Jurun

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Focus of this paper is description and functioning manner of the instrument for wave pressure metering. Moreover, an essential component of this paper is the proposal of a metering unit for the direct wave pressure measurement determined by the shape and surface of the instrument including the number of sensors and angle between them. Namely, far applied instruments by means of height, length, direction, wave time period and other components determine wave pressure on a particular area. This instrument, allows the direct measurement i.e. measurement without additional calculation, of the wave pressure expressed in a standardized unit of measure. That way the instrument has a standardized form, surface, number of sensors and the angle between them. In addition, it is made with the status that follows the wave and always is on the water surface. Database quality which is listed by the instrument is made possible by using the Arduino chip. This chip is programmed for receiving by two data from each of the sensors each second. From these data by a pre-defined manner a unique representative value is estimated. By this procedure all relevant wave pressure measurement results are directly and immediately registered. Final goal of establishing such a rich database is a comprehensive statistical analysis that ranges from multi-criteria analysis across different modeling and parameters testing to hypothesis accepting relating to the widest variety of man-made activities such as filling of beaches, security cages for aquaculture, bridges construction.

Keywords: instrument, metering, water, waves

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Authors: Chen-Yu Tsai, Wen-Te Liu, Chen-Chen Lo, Kang Lo, Yin-Tzu Lin

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Background: Driving drowsiness related to insufficient or disordered sleep accounts for a major percentage of vehicular accidents. Sleep deprivation is the primary reason related to low sleep efficiency. Nevertheless, the mechanism of sleep deprivation induces driving fatigue to remain unclear. Objective: The objective of this study is to associate the relationship between insufficient sleep efficiency and driving fatigue. Methodologies: The physical condition while driving was obtained from the questionnaires to classify the state of driving fatigue. Sleep efficiency was quantified as the polysomnography (PSG), and the sleep stages were sentenced by the reregistered Technologist during examination in a hospital in New Taipei City (Taiwan). The independent T-test was used to investigate the correlation between sleep efficiency, sleep stages ratio, and driving drowsiness. Results: There were 880 subjects recruited in this study, who had been done polysomnography for evaluating severity for obstructive sleep apnea syndrome (OSAS) as well as completed the driver condition questionnaire. Four-hundred-eighty-four subjects (55%) were classified as fatigue group, and 396 subjects (45%) were served as the control group. The ratio of stage three sleep (N3) (0.032 ± 0.056) in fatigue group were significantly lower than the control group (p < 0.01). The significantly higher value of snoring index (242.14 ± 205.51 /hours) was observed in the fatigue group (p < 0.01). Conclusion: We observe the considerable correlation between deep sleep reduce and driving drowsiness. To avoid drowsy driving, the sleep deprivation, and the snoring events during the sleeping time should be monitored and alleviated.

Keywords: driving drowsiness, sleep deprivation, stage three sleep, snoring index

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Authors: Oladipo Oluwaseun Peter

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Daily consumption of crude oil is alarming as a result of increasing demand for energy. Waste generation tends to rise with the level of economic advancement of a nation. Hence, this project work researches how wastes which could pose toxic if left unattended to can be processed through biodigestion in order to generate biofuel which could serve as a good substitute for petroleum, a non renewable energy source, so as to reduce over-dependence on petroleum and to prevent environmental pollution. Anaerobic digestion was carried out on organic wastes comprising brewery spent grains, rice husks and poultry droppings in a plastic biodigester of 1000 liters volume using the poultry droppings as a natural inoculums source. The feed composition in ratio 5:3:2, spent grain, rice husks and poultry droppings were mixed with water in the ratio 1:6. Thus, 600 Kg of water was used to prepare the slurry with 100 Kg of feed materials. A plastic biodigester was successfully constructed, and the problem of corrosion and rusting were completely overcome as a result of the use of non-corroding materials of construction. A reasonable quantity of biogas, 33.63m3, was generated over a period of 60 days of biodigestion. The bioslurry was processed through two different process routes; evaporation and filteration. Evaporation process of analysis shows high values of 0.64%, 2.11% and 0.034% for nitrogen, phosphorous and potassium respectively, while filteration process gives 00.61%, 1.93% and 0.026% for nitrogen, phosphorous and potassium respectively.

Keywords: biodigestion, biofuel, digestion, slurry, biogas

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Authors: H. Tounsadi, A. Khalidi, M. Abdennouri, N. Barka

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The objective of this study was to produce high quality activated carbons from Diplotaxis harra biomass by potassium hydroxide activation and their application for heavy metals removal. To reduce the number of experiments, full factorial experimental design at two levels were carried out to occur optimal preparation conditions and better conditions for the removal of cadmium and cobalt ions from aqueous solutions. The influence of different variables during the activation process, such as carbonization temperature, activation temperature, activation time and impregnation ratio (g KOH/g carbon) have been investigated, and the best production conditions were determined. The experimental results showed that removal of cadmium and cobalt ions onto activated carbons was more sensitive to methylene blue index instead of iodine number. Although, the removal of cadmium and cobalt ions is more influenced by activation temperature with a negative effect followed by the impregnation ratio with a positive impact. Based on the statistical data, the best conditions for the removal of cadmium and cobalt by prepared activated carbons have been established. The maximum iodine number and methylene blue index obtained under these conditions and the greater sorption capacities for cadmium and cobalt were investigated. These sorption capacities were greater than those of a commercial activated carbon used in water treatment.

Keywords: activated carbon, cadmium, cobalt, Diplotaxis harra, experimental design, potassium hydroxide

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Authors: Antar Bouhank, Youcef Beellal, Samir Adjel, Abdelmadjid Ababsa

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This paper investigates the impact of 3D printing parameters using the cold metal transfer (CMT) technique on the morphological, mechanical, and tribological properties of walls and massive parts made from aluminum alloy. The parameters studied include current intensity, torch movement speed, printing increment, and the flow rate of shielding gas. The manufactured parts, using the technique mentioned above, are walls and massive parts with different filling strategies, using grid and zigzag patterns and at different current intensities. The main goal of the article is to find out the welding parameters suitable for having parts with low defects and improved properties from the previously mentioned properties point of view. It has been observed from the results thus obtained that the high current intensity causes rapid solidification, resulting in high porosity and low hardness values. However, the high current intensity can cause very rapid solidification, which increases the melting point, and the part remains in the most stable shape. Furthermore, the results show that there is an evident relationship between hardness, coefficient of friction and wear test where the high intensity is, the low hardness is. The same note is for the coefficient of friction. The micrography of the walls shows a random granular structure with fine grain boundaries with a different grain size. Some interesting results are presented in this paper.

Keywords: aluminum alloy, porosity, microstructures, hardness

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Authors: Sana Eid, Ahmad S. Darwish, Tarek Lemaoui, Maguy Abi Jaoude, Fawzi Banat, Shadi W. Hasan, Inas M. AlNashef

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Addressing the growing challenge of per- and polyfluoroalkyl substances (PFAS) pollution in water bodies, this study introduces natural deep eutectic solvents (NADESs) as a pioneering solution for the efficient extraction of perfluorooctanoic acid (PFOA), one of the most persistent and concerning PFAS pollutants. Among the tested NADESs, trioctylphosphine oxide: lauric acid (TOPO:LauA) in a 1:1 molar ratio was distinguished as the most effective, achieving an extraction efficiency of approximately 99.52% at a solvent-to-feed (S:F) ratio of 1:2, room temperature, and neutral pH. This efficiency is achieved within a notably short mixing time of only one min, which is significantly less than the time required by conventional methods, underscoring the potential of TOPO:LauA for rapid and effective PFAS remediation. TOPO:LauA maintained consistent performance across various operational parameters, including a range of initial PFOA concentrations (0.1 ppm to 1000 ppm), temperatures (15 °C to 100 °C), pH values (3 to 9), and S:F ratios (2:3 to 1:7), demonstrating its versatility and robustness. Furthermore, its effectiveness was consistently high over seven consecutive extraction cycles, highlighting TOPO:LauA as a sustainable, environmentally friendly alternative to hazardous organic solvents, with promising applications for reliable, repeatable use in combating persistent water pollutants such as PFOA.

Keywords: deep eutectic solvents, natural deep eutectic solvents, perfluorooctanoic acid, water remediation

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Authors: Ratna Dewi Kusumaningtyas, Riris Pristiyani, Heny Dewajani

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Biodiesel is commonly produced via the two main routes, i.e. the transesterification of triglycerides and the esterification of free fatty acid (FFA) using short-chain alcohols. Both the two routes have drawback in term of the side product yielded during the reaction. Transesterification reaction of triglyceride results in glycerol as side product. On the other hand, FFA esterification brings in water as side product. Both glycerol and water in the biodiesel production are managed as waste. Hence, a separation process is necessary to obtain a high purity biodiesel. Meanwhile, separation processes is generally the most capital and energy intensive part in industrial process. Therefore, to reduce the separation process, it is essential to produce biodiesel via an alternative route eliminating glycerol or water side-products. In this work, biodiesel synthesis was performed using a glycerol-free process through chemical interesterification of jatropha oil with ethyl acetate in the presence on sodium acetate catalyst. By using this method, triacetine, which is known as fuel bio-additive, is yielded instead of glycerol. This research studied the effects of catalyst concentration on the jatropha oil interesterification process in the range of 0.5 – 1.25% w/w oil. The reaction temperature and molar ratio of oil to ethyl acetate were varied at 50, 60, and 70°C, and 1:6, 1:9, 1:15, 1:30, and 1:60, respectively. The reaction time was evaluated from 0 to 8 hours. It was revealed that the best yield was obtained with the catalyst concentration of 0.5%, reaction temperature of 70 °C, molar ratio of oil to ethyl acetate at 1:60, at 6 hours reaction time.

Keywords: biodiesel, interesterification, glycerol-free, triacetine, jatropha oil

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